A lighting effect that involves fast movements, intensity changes, or a variety of colors to help build excitement and celebration during an event

A filter that removes or attenuates frequencies above and below the centre frequency at which it is set, and only passes a specific range of frequencies. Band-pass filters are often used in synthesizers as tone shaping elements.

The range of signal frequencies that a piece of audio or video equipment can encode or decode; the difference between the limiting frequencies of a continuous frequency band. Video uses higher frequency than audio, thus requires a wider bandwidth

The range of frequencies passed by an electronic circuit such as an amplifier, mixer or filter. The frequency range is usually measured at the points where the level drops by 3dB relative to the maximum

1. A group of luminaires 2. A group of dimmers or dimmer modules 3. A group of sliders or channels on a control console

A specific configuration of sounds or other parameters stored in memory and accessed manually or via MIDI commands.

Also known as TT or Tiny Telephone Plugs. A professional form of miniature jack plug derived from the telecommunications industry and widely used for balanced mic and line-level connections on professional patch bays.

Leads without a connector installed

Water vessel from which fireworks are discharged.

An apparatus with adjustable flaps, usually 2, 4, or 8, that attaches to the front of a luminaire. It is used to block or shape the beam.

A rapidly fired sequence of aerial fireworks.

From the French term�barr�. The technique of placing the left hand index finger over two to six strings in the fingering of a chord. The great advantage of using barre chords is that they are "moveable shapes" that can be applied at practically any fret.

A male turn-around, generally used for the connection of control cables.

1. The bottom of a stand used for mounting luminaires. 2. The part of a lamp to which the electrical connections are made, i.e., the part with the contacts. It is often the mechanical support and/or heat sink for the lamp. 3. The flat, bottom support for some luminaires.

A metal plate which prevents damage to floors when using scaffolding or trussing

The metal cradle that holds the snare drum.

The generic term for using a basket hitch with an extra shackle to ease or speed fitting or removing slings at height or in awkward situations

The lowest pitched drum in a marching band or with a drumset. As it refers to a drumset, it is also called a kick drum because it is 'kicked' with your foot via a foot pedal. A marching bass drum is usually mounted and worn to be played while marching and struck from either side with the hands using a large felt mallet beater. The drumset bass drum or kick sits on the floor with the head facing toward you. As a type of tom-tom, the bass drum can also be tuned but unlike a tom tom drum which usually requires a drum key, most kick drums have T-shaped rods that can be tuned by simply turning those rods.

Pedal used to play the bass drum

A guitar that has the same pitch and tuning as a double bass, usually electrically

The frequency response of a loudspeaker system at the lower end of the spectrum. The physical size and design of a loudspeaker cabinet and the bass driver (woofer) determine the low frequency extension (the lowest frequency the speaker can reproduce at normal level) and the how quickly the signal level falls below that frequency.

A special type of acoustic absorber which is optimised to absorb low frequency sound waves.

A double headed, hour glass shaped drum originating from Nigeria. It later migrated to Cuba and eventually to the US. These drums can be played in the lap or with a strap around the neck.

A horizontal pipe on which luminaires, scenery, curtains, and some distribution equipment are hung.

Typically referring to a drumhead that has a coated surface. It's also a term referring to the "playing" side of the drum.

A collection of fireworks devices, such as a group of mortars (finale battery) or a bundle of roman candles (candle battery,) fused together in such a manner that they are fired within a short period of time.

Generally, the conoid, or in some cases, the pyramoid of light emanating from a luminaire.

The angle of the vertex of a cone shaped beam where the perimeter of the base is defined by where the intensity is 50% of the maximum intensity.

The complete shape of the beam, as defined in the general sense. It includes any realistic or abstract patterns introduced into the beam as well as any apparatus that alters the contour of the beam.

The angle of the vertex of a cone shaped beam where the perimeter of the base is defined by where the intensity is 10% of the maximum intensity.

The edge of the drum that the head sits on. Bearing edges are often sharpened to a smaller angle for greater attack, projection and evenness of tone.

A term popularized in drumming over the last 10 years. It refers to permutation where all beats will move forward say, one eighth note. This method will create numerous variations of rhythmic possibilities on the drums.

A drumstick (usually with a mallet-type head) that beats a drum. Also, the rod and ball mechanism on a bass drum foot pedal is called a beater. It "beats" the bass drum.

Actions of rope management in arresting falls. The belay is the attachment point to a structure. The belayer is the person tending the rope and belaying equipment.

The raised center of the cymbal, usually about 4" or so in diameter. This part of the cymbal creates a sharper, more defined cutting sound. Drummers often use it to play accentuated passages.

Part of the communication ('cans') system in a theatre, the Beltpack contains the controls and circuitry to drive the HEADSET worn by crew members. Each beltpack connects into the headset ring and back to a PSU (Power Supply Unit) which is powered from the mains.

The act of pushing or pulling a string sideways across the a fret to raise the pitch of a note by a half to full tone or more. Used extensively in rock and blues playing as well as in jazz.

A synthesizer than can generate two different sounds simultaneously

A high-frequency signal used in analogue recording to improve the accuracy of the recorded signal and to drive the erase head. Bias is generated by a bias oscillator.

A counting system based on only two states: 1s and 0s. It is ideal for electronic equipment where it can be represented as high and low voltages, light on/off, N-S or S-N magnetic domains, etc.

A two-component powder which when separate, are a flammable solid and an oxidizer. Bottles are usually labeled �A� (oxidizer) and �B� (fuel). When mixed together, they become a pyrotechnic composition. Effects vary, including but not limited to: Airburst, Concussion, Flash, Smoke, Fast and Slow Sparkle and Sparks. Most binaries are used in specific hardware to control their effect, such as flash pots, sparkle pots and concussion mortars. However, when used for making airburst, binary powders are usually assembled in self-consuming plastic film or flash paper capsules or bags.

A contraction of Binary digit, which may either be 1 or 0.

The number of levels that a pixel might have, such as 256 with an 8-bit depth or 1024 with a 10-bit depth

The rate at which the compressed bit stream is delivered from the storage medium to the input of a decoder. The digital equivalent of analog bandwidth.

The number of data bits replayed or transferred in a given period of time (normally one second). Normally expressed in terms of kb/s (kilo bits per second) or Mb/s (mega bits per second). For example, the bit rate of a standard CD is (2 channels x 16 bits per sample x 44.1 thousand samples per second) = 1411.2 kilobits/second. Popular MP3 file format bit�rates range from 128kb/s to 320kb/s, while the Dolby Digital 5.1 surround soundtrack on a DVD-Video typically ranges between 384 and 448kb/s.

An accidentally unlit portion of the stage.

A luminaire with a beam whose wavelengths are too short to be visible, i.e., 320 to 380 nm. These ultraviolet wavelengths excite fluorescent materials, paints, etc., in theatrical applications.

A fuse made from string that is impregnated with Black Powder.

Material found in fireworks. This material can be used as a propellant charge, to produce sound, as a constituent of other compositions, or in the ignition fuse or timing system of fireworks. Also known as gun powder.

To remove or the removal of all or almost all light on the performing area, usually done rapidly.

1. Black clothing worn by stage workers during productions. 2. Any black drapes permanently or temporarily rigges

Blast beats are alternating single-stroke rolls broken up between the snare drum and the bass drum. The hand that plays the ride cymbal generally plays in unison with the bass drum. Blast beats are most often heard in heavy metal drumming and extreme drumming.

The effect created by adjusting the intensity of the illumination directly on a theatrical scrim inversely with the intensity of the illumination behind it. This causes the scrim to go through a phase of changing transmission.

1. Lamps arranged around the stage directed into the auditorium, originally to prevent spectators seeing the stage during scene changes when the house tabs were not lowered. Now used for effect in rock concerts etc. 2. A strip of dense black material fastened behind a crack between two flats or scenic pieces to prevent light leak. Cloth hung behind a gauze to prevent transparency before the effect is required.

Blue lights used backstage in a performance situation. See also working lights.

The main control for the stage lighting. Originally known as the switchboard or dimmerboard, it is now usually remote from the dimmers. The lighting operator for a show is said to be "on the board", and is sometimes known as the "board op". In the US, the board operator is said to be "running the lights".

An Irish drum covered with goatskin

Metal bin or box where certain explosives can be safely detonated

A pair of small drums that are connected in the middle and played with your hands. Very common in Afro-Cuban music and Latin percussion.

An arm that extends from the cymbal stand to allow greater positioning around the drumset. Most drummers use it to bring the cymbals in closer to them.

A mechanical means of supporting a microphone above a sound source. Many microphone stands are supplied with a �boom arm� affixed to the top of the stand�s main vertical mast. The term may also be applied to larger, remotely controlled microphone supports used in film and TV studios, or even to the handheld �fishpoles� used by film and TV sound recordists.

Long colorful tubes that produces various tones. Popular kid's percussion instrument common in musical education. Many elementary schools and junior high schools incorporate BoomWhackers into their music curriculum.

Having an excessive accentuation on the tones of lower pitch in reproduced sound

A single gain control which allows the range of frequencies passing through a filter to be either amplified or attenuated. The centre position is usually the 'flat' or 'no effect' position.

A striplight often used at some border on a stage or over a stage. This could be an area between two curtains or at the edge of the stage floor, cyclorama, runway, etc.

Sudden variations in picture presentation (brightness, size, etc.,) independent of scene illumination.

The process of mixing two or more recorded tracks together and re-recording these onto another track.

A physical obstruction to sound waves, such as a wall, or a large solid object. When sound waves reach a boundary they create a high pressure area at the surface.

Fountains fired in groups.�

Most riggers' knot of choice. Secure and easy to undo after heavy loading

An individual burst from an aerial shell, generally producing either a visual effect (stars) or noise (salute).

A special power cord that has one male or female multiconnector electrically connected to a plurality of female or male connectors, respectively, via separate cables or sets of sleeved wires. In most cases, each contact of the multiconnector is electrically connected to only one of all of the collective contacts on the other connectors.

A commonly used abstract GOBO which gives a textured effect to the light, without throwing a specific pattern onto the stage. Used to add interest to light beams. A leafy breakup is used for outdoor scenes / forests / spooky wood etc. to break up the light on the actors faces.

The part of the guitar where the strings transmit their vibrations to the soundboard. Made of either wood or metal.

An elevator which raises and lowers sections of the stage floor, usually by electrical or hydraulic means.

Used to locate the string percisely in the horizontal plane. Usually made of steel

A V-shaped arrangement of lifting equipment or rigging materials that enable load to be spread or shared between the "legs" of the bridle.

Reproducing high-pitched sounds

The attribute of visual perception in accordance with which an area appear to emit more of less light.

Brushes as they relate to drumming have wire bristles that fan out and are used mostly with traditional jazz drumming. Drummers that play brushes utilize "snaps" and "sweeps" to create a unique art form that we call "brush technique".

A machine that emits a continuous stream of soap-based bubbles.

1. During lighting plotting, to construct a state from blackout, or to an existing state. 2. An increase in light or sound level. 3. A period of set construction

To change the intensity of a luminaire or group of luminaires instantaneously, usually for a short duration of time, often to the beat of music as if to create a pulsing effect.

Federal agency which regulates the licensing and storage of display fireworks. This agency monitors the importation, manufacture, distribution, and storage of display fireworks.

Sackcloth hessian, used as softening under steel wire rope slings. Used because it's flexible and easy to use, and will not cause injury when dropped.

Also called burn. An image which persists in a fixed position in the output signal of a camera tube after the camera has been turned to a different scene or, on a monitor screen.

The melting of a lamp filament

A conductor comprising a thick metal strip, usually copper, brass, or aluminum, to which other devices, such as fuses and circuit breakers, as well as a means to make electrical connections, may be attached. Buses are often used in power distribution equipment that handle large amounts of electrical current, e.g., panelboards and switchboards

An electrical signal path along which multiple signals may travel. A typical audio mixer contains several (mix) busses which carry the stereo mix, subgroups, the PFL signal, the aux sends, and so on. Power supplies are also fed along busses.

A collection of digital data comprising eight bits.

A "C" shaped clamp that attaches onto a pipe and locks with the aid of a bolt, that when tightened, presses like a vice onto the pipe. It also has a stud or studs for the attachment of luminaire, grip equipment, etc

A recordable type of Compact Disc that can only be recorded once - it cannot be erased and reused.�

Content Distribution Network

Computer Generated Imagery. Any images or special effects sequence in a video created in any motion graphics or special effects compositing software

Columbus McKinnon Corporation. American manufacturer of lifting equipment

Cyan, Magenta, Yellow. The three secondary colors of light that are used for color mixing in moving lights

Central Processing Unit � the number-crunching heart of a computer or other data processor.

The physical construction which encloses and supports the loudspeaker drive units. Usually built of wood or wood composites (although other materials are often used including metal alloys and mineral composites). Cabinets can be �sealed� or �vented� in various ways, the precise design influencing the bass and time-domain characteristics.

1. A rope of wire used to transmit electricity or data. 2. To run, hook up, and/or interconnect electrical cables and the items to which the cables are connected. 3. A strong, flexible, wire rope made of steel, used to support pipes, battens, truss, etc., from an overhead structure.

A group of electric cables attached at various points by tape, rope, etc.

A metal sling used to support heavy stage cable as it hangs from a batten, while simultaneously preventing the cable from entering horizontal sight lines from the house to the stage. It can also take strain away from the point where the cable exits a piece of distribution equipment.

An overhead electric cable or group of electric cables that extends downward for the connection of luminaires or other electrical apparatuses. The cable(s) may be connected to some type of overhead support, or directly to a piece of distribution equipment.

A hook that attaches to a stand used to hold excess coils of electric cable, often found on follow spot stands.

A term used to describe a connector designed to be electrically attached to the end of a cable.

Lockable (and sometimes releasable) plastic strap used to tie a bundle of cables together, amongst many other things.

A hollow wooden box that has the tone of a conga. Non-tuneable as it has no drumhead. Origin - Latin America

A chain-fused firework that propels a series of aerial shell, comet or mine effects into the air from collectively attached tubes.

1. A notification of a working session. 2. The period of time to which the above call refers. 3. Instructing or directing (i.e. Calling spotlight cues)

The production crew arrives early to set up the stage, assemble the�backline�(musical equipment provided by the venue), and prepare the sound and lighting systems.

A commonly used type of insulated, locking, single conductor cable connector manufactured by Crouse-Hinds Inc. The name Cam-lok is trademarked.

Professional operator of a film or video camera

The unit of Luminous Intensity of a light source.

A term often used in place of Luminous Intensity.

A passive, two-terminal electrical component which stores energy in the form of an electrostatic field. The terminals are attached to conductive �plates� which are separated by a non-conductive dielectric. Capacitance is measured in Farads. If a voltage is applied across the terminals of a capacitor a static electric field develops across the dielectric, with positive charge collecting on one plate and negative charge on the other. Where the applied voltage is an alternating signal, a capacitor can be thought of as a form of AC resistance that reduces with increasing signal frequency. The old-fashioned term is a �condensor�.

A device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator

A mechanical barre that attaches to the neck of a guitar by means of a string, spring, elastic or nylon band, or a lever and thumbscrew arrangement. The capo can be used to raise the key of a song to suit a vocalist as well as to lower the action and shorten the string length.

An alternative term for a transducer which converts acoustic sound waves into an electrical signal.

Spring-loaded clip device used by climbers and also in stage rigging. Named after the carbine gun which had a spring loaded gate.

An arc source in which the arc is formed in air between a pair of carbon electrodes.

An obsolete form of microphone in which carbon granules�are contained between two metal contact plates, one of which acts as the diaphragm and moves in response to sound waves. The microphone has to be biased with a DC voltage which�causes a current to pass�from one metal contact plate, through the carbon granules, to the other metal contact plate. The varying pressure exerted on the carbon granules by the moving diaphgram causes a varying resistance and thus a varying current�which is analogous to the sound waves. Carbon Button Microphones were used in the very early days of sound recording�and broadcasting, as well as in domestic telephones up until the 1980s when electret capsules became more commonplace.

In general, a circuit board.

A specific form of polar response of a unidirectional microphone or loudspeaker. It is an inverted heart-shape which has very low sensitivity at the back (180 degrees), but only slightly reduced sensitivity (typically between 3 and 6dB) at the sides (90/270 degrees).

Cable is used in structured cabling for computer networks such as Ethernet over twisted pair

Horizontal wire rope under tension.

A raised, overhead platform used in film industry studios, used for mounting and accessing luminaires and other types of production equipment. Located around the perimeter of the studio floor, they are often painted green and are always provided with handrails.

A bass instrument of the violin family, held upright on the floor between the legs of the seated player

A member of an officially accredited professional body of accountants

A series of two or more aerial shells fused to fire in sequence from a single ignition.

Period where the crew tears down the equipment used for one act and resets the stage for the next act.

A path carrying for audio or data. In the context of a mixing console a channel is a single strip of controls relating to one input. In the context of MIDI, Channel refers to one of 16 possible data channels over which MIDI data may be sent. The organisation of data by channels means that up to 16 different MIDI instruments or parts may be addressed using a single cable.

An individual control output on a control console, accessed and regulated by a slider, switch, or button, or in, some cases, accessed by a discretely assigned address and regulated by a data input apparatus.

A semiconductor device that converts optical images to electronic signals. CCDs are the most commonly found type of image sensor in consumer camcorders and video cameras.

A repeated sequence of changing lighting states. A chase can be produced easily by the effects functions of a computerised lighting desk. There are standalone units designed to chase lighting circuits electronically in time to music (sound to light) or mechanically as a repeated sequence (as used in early neon signs).

A device used for connecting iron pipe or aluminum tube, usually to create a lighting position

All pyrotechnic and explosive composition contained in a fireworks device. Inert materials (such as clay used for plugs or organic matter used for density) are not considered to be part of chemical composition.

A row of small, thin tubular bells that are brushed with the hand or gently with a drumstick or mallet. Chimes are often used in a soft ballad. See also "Tubular Bells".

Also referred to as a "pang" cymbal. The china cymbal creates a gong-like sound or as some would refer to as a "trashy" type of sound.

A sling pattern made by passing one end of a sling through the opposite end's eye or by marking a loop with an endless sling

Your technique or rhythmic vocabulary.�

The main horizontal in a truss/lattice structure

Three or more notes sounded simultaneously.

An effect created by doubling a signal and adding delay and pitch modulation, intended to make a single source sound more like an ensemble.

Strictly speaking, the portion of a song lyric or melody that is repeated, often with other voices joining in. In jazz improvisation, however, "playing a chorus" would mean taking a turn improvising over the tune's chords progression.

The quality of color that embraces both hue and saturation. White, black, and grays have no chroma

A scale of pitches rising or falling in semitone steps.

An optical defect of a lens that causes different colors or wavelengths of light to be focused at different distances from the lens. It is seen as color fringes or halos along edges and around every point in the image.

The color quality of light that is defined by the wavelength (hue) and saturation. Chromaticity defines all the qualities of color except its brightness.

A complete electrical path leading from an electrical supply through conductors and perhaps dimmers, distribution equipment, electrical devices, electronic items, etc. to the load and returning to the source. The load is quite often a lamp.

A plastic or fibrous card that contains electronic components and the wiring and/or tracers that interconnect them.

An electrical device designed to open and close a circuit by non-automatic means and to open the circuit automatically on a predetermined over current without damage to itself.

A rhythm made up of a 2 bar phrase played as 2:3 clave (ex: 1 2,1 2 3) or 3:2 clave (ex: 1 2 3,1 2). Once the song starts, the clave will not change. Latin American countries often clap their hands to clave during the music.

Percussion instrument; a pair of cylindrical wooden sticks (usually around an inch and half thick) that are clicked together to make a high pitched sound marking clave in Latin music. Sometimes made from synthetic material.

An audible metronome pulse which assists musicians in playing in time.

When an audio signal is allowed to overload the system conveying it, clipping is said to have occurred and severe distortion results. The �clipping point� is reached when the audio system can no longer accommodate the signal amplitude �either because an analogue signal voltage nears or exceeds the circuitry�s power supply voltage, or because a digital sample amplitude exceeds the quantiser�s number range. In both cases, the result is that the signal peaks are �clipped� because the system can�t support the peak excursions � a sinewave source signal becomes more like a squarewave. In an analogue system clipping produces strong harmonic distortion artefacts at frequencies above the fundamental. In a digital system those high frequency harmonics cause aliasing which results in anharmonic distortion where the distortion artefacts reproduce at frequencies below the source fundamental. This is why digital clipping sounds so unlike analogue clipping, and is far more unpleasant and less musical.

An electronic limit usually imposed in cameras to avoid overly bright or dark signals. When improperly applied can result in loss of picture information in very bright or very dark areas; Also used in switchers to set the cutoff point for mixing video signals. The electronic process of shearing off the peaks of either the white or black excursions of a video signal for limiting purposes. Sometimes, clipping is performed prior to modulation, and sometimes to limit the signal, so it will not exceed a predetermined level

The process of controlling the sample rate of one digital device with an external clock signal derived from another device. In a conventional digital system there must be only one master clock device, with everything else �clocked� or �slaved� from that master.

An exact duplicate. Often refers to digital copies of digital tapes.

Generally, to make one type of fixture act as something else

A mic technique which involves placing a microphone very close to a sound source, normally with the intention of maximising the wanted sound and minimising any unwanted sound from other nearby sound sources or the room acoustics. IN classic music circles the technique is more often known as 'Accent�Miking'.

Video primarily used for surveillance and security that is not broadcast to the general public.

A common type of knot that is useful for many applications

Purposely designed chain system forging that allows a link of sling chain to be grabbed in order to shorten the reach length of the chain

The drumset accessory that holds the top cymbal, of the hi hat cymbals, in place on the rod.

A particular type of cable capable of passing a wide range of frequencies with very low signal loss. Such a cable in its simplest form consists of a hollow metallic shield with a single wire accurately placed along the center of the shield and isolated from the shield.

1. The algorithm used to capture analog video or audio in digital form. 2. A device for converting signals from analog to coded digital and then back again for use in digital transmission schemes. Most codecs employ proprietary coding algorithms for data compression

A means of arranging two or more directional microphone capsules such that they receive sound waves from all directions at exactly the same time. The varying sensitivity to sound arriving from different directions due to the directional polar patterns means that information about the directions of sound sources is captured in the form of level differences between the capsule outputs. Specific forms of coincident microphones include �XY� and �MS� configurations, as well as B-format and Ambisonic arrays. Coincident arrays are entirely mono-compatible because there are no timing differences between channels.

A mirror that transmits heat, i.e., infrared radiation, but reflects light.

A term used to describe the ignition of a cold arc lamp, i.e., a lamp that has not been electrified for a relatively long period of time.

To place color media in front of a luminaire to alter the color of the beam.

An arrangement of hue, chroma, and value within a design that produces a sense of equilibrium, i.e., no colored area commands attention to the detriment of the entire arrangement.

An apparatus that attaches to a luminaire and allows one to manually introduce one or more color frames into the beam. Color changers are most often found on follow spots.

Process of using color gels, or filters, to alter the overall color of the light

Adjusting the color temperatures of various luminaires so that they are all the same, or to make them match existing light sources, e. g., sunlight or fluorescent light. This is usually accomplished by utilizing color media, but adjusting the input voltage levels is a method sometimes used for some luminaires.

Extraneous colors appearing at the edges of colored objects, and differing from the true colors in the object.

An apparatus used to hold color media or other types of filters. It can be of various shapes and sizes, and may comprise one or more pieces.

Any colored transparent material that con be placed in front of a beam to color the light. They can be of the absorption or reflection type.

1. Additive color mixing involves two differently colored beams of light onto the same area. Both primary and complementary colors each mix to form white. 2. Subtractive color mixing includes placing two gels in front of the same lamp.

A single number approximate evaluation of the effect of a light source on the visual appearance of a colored surface. The number falls on a scale from below 0 to 100, with daylight at 100. Objects and people viewed under lamps with a high CRI generally appear more true to life.

A measure of the ability of a light source to reveal the colors of objects in comparison with an ideal natural light source

The degree to which a color is free of white light.

An electronic, motorized apparatus that mounts on the front of a luminaire, and allows for the automatic placement of one of a number of gels to be placed in front of the beam.

The temperature, in degrees Kelvin, of a black-body that generates light with the closest visual color match to the source being specified, i.e., a measure of the color appearance of light, not the actual temperature of the light.

An apparatus holding several different gels that can be rotated by hand or motor such that any one gel can be placed in front of a luminaire with relative ease.

A distortion of the natural timbre or frequency response of sound, usually but not always unwanted.

A cartridge which plugs into a flash pot, and when detonated, produces an intense cloud of colored smoke. Can stain colored objects or costumes though.

A series of deep filter notches created when a signal is combined with a delayed version of itself. The delay time (typically less than 10ms) determines the lowest frequency at which the filter notches start.

A lever hoist or tackle set designed for tensioning of pulling

A device containing a single pellet of selfconsuming pyrotechnic composition. The comet is propelled into the air via a lifting charge producing various colors, glitter and crackle effects. Typically, proximate audience comets do not exceed 2 inches (50mm) in diameter and are self-contained devices including the effect, lift charge, mortar and igniter

A measure of how well a balanced circuit rejects an interference signal that is common to both sides of the balanced connection.

4/4 time, indicating 4 beats to the measure with the quarter note receiving the beat.

An encode-decode device typically employed to pass a wide dynamic range signal over a channel with a lower dynamic range capability. The source signal is compressed in the encoder to reduce the dynamic range, and subsequently expanded by the decoder to restore the original dynamics. The Dolby noise reduction codecs are examples of companders.

Short for �compilation.� The process of recording the same performance (e.g. a lead vocal) several times on multiple tracks to allow the subsequent selection of the best sections and assembling them to create a �compilation� performance which would be constructed on a final track.

Two colors of light that combine to make white light in the additive color mixing system. For red, green, and blue, the complementary colors are cyan, magenta, and yellow, respectively.

Two colors in the additive color mixing system that combine to make nearly white light.

The combined picture signal, including vertical and horizontal blanking and synchronizing signals.

1. The process of electronically processing a digital video picture to make it use less storage or to allow more video to be sent down a transmission channel. 2. The process of removing picture data to decrease the size of a video image. 3. The reduction in the volume of data from any given process so that more data can be stored in a smaller space. There are a variety of compression schemes that can be applied to data of which MPEG-1 and MPEG-2 are called lossy since the data produced by compression is not totally recoverable. There are other compression schemes that are totally recoverable, but the degree of compression is much more limited

A small specialized diaphragm loudspeaker which generates the sound in a horn loudspeaker

A device (analogue or digital) which is designed to reduce the overall dynamic range of an audio signal either by attenuating the signal if it exceeds a set threshold level according, or by increasing the level of quiet signals below a threshold. The amount of attenuation is defined by a set ratio, while the speed of response (attack) and recovery (release) can usually also be controlled.

Memory board

Using a computer to help with 2D plans and drawings, or increasingly for 3D visualisation of how a set will look, and how lighting will affect it.�

A term used to describe a lens side that is inwardly and usually spherically curved.

This is a specific form of electrostatic microphone which operates on the principle of measuring the change in electrical voltage across a capacitor. The capacitor is formed from two metal electrodes, one fixed (the back-plate) and the other a thin conductive membrane that flexes in response to sound pressure.�

To carry electrical current.

A material that provides a low resistance path for electrical current.

Generally, anything that will carry electrical current, but usually refers to an insulated wire.

A specific shape of drive unit diaphragm intended to push and pull the air to create acoustic sound waves. Most bass drivers use cone-shaped diaphragms, where the electromagnetic motor of the drive unit is connected to the point of the cone, and its outer diameter is supported by some form of flexible membrane.

A soft light luminaire that uses a single ended lamp and a cone shaped reflector.

A drum with African/Cuban origin that is played with the hands. Shaped like a barrel, it sits on the floor or on a stand and can be played sitting or standing. It has a head on one side only. The conga is the "middle" drum of a typical conga set of drums.

1. Specifically, the name for a family of electrical wiring devices, such as plugs and receptacles, comprising one or more contacts, a means for electrically attaching a conductor to each contact, a means for electrically insulating each contact from the other, and an overall insulating material around the complete assembly such that only the contacts are exposed when the connector is properly installed to the item containing the conductors. 2. Generally, any item used to make an electrical connection between two or more separate conductors.

A piece of power distribution equipment comprising an elongated metal housing, and a plurality of female flush mount connectors or female pigtail connectors for the purpose of supplying electricity to luminaires. It usually hangs from a batten and has many circuits, the line side is usually hard-wired, and it gets its electrical supply from dimmers.

An alternative term for mixer

An electronic apparatus, run by an operator, that converts the settings of various items, such as sliders, switches, buttons, or some form of data input, into a digital or analog signal that is thereby transmitted to a control card, dimmer bank, or some other electronic apparatus. Some control consoles are also equipped with monitors.

Also known as 1.4G fireworks. Fireworks that are intended for use by the consumer. The permitted usage of consumer fireworks varies by state. Examples are fountains, cones, and firecrackers.

(CPSC) Federal agency which regulates consumer 1.4G fireworks.

An alternative plan of action if a piece of technology fails to operate

AKA Independent Contractor; a person, business, or corporation that provides goods or services to another entity under terms specified in a contract or verbal agreement; NOT AN EMPLOYEE

The range of light to dark values in a picture or the ratio between the maximum and minimum brightness values.

1. Specifically, a circuit board that receives the control signal from the control console and, in turn, individually controls the independent outputs of a bank of dimmer modules. 2. Generally, any circuit board that performs many of the control functions of an electronic apparatus, e. g., a ballast or automated light.

A variable voltage signal typically used to control the pitch of an oscillator or filter frequency in an analogue synthesizer. Most analogue synthesizers follow a one volt per octave convention, though there are exceptions. To use a pre-MIDI analogue synthesizer under MIDI control, a MIDI to CV converter is required.

A device which transcodes audio signals between the analogue and digital domains. An analogue-to-digital (A-D) converter accepts an analogue signal and converts it to a digital format, while a digital-to-analogue (D-A) converter does the reverse. The sample rate and wordlength of the digital format is often adjustable, as is the relative amplitude of analogue signal for a given digital level.

A term used to describe a lens side that is outwardly and usually spherically curved.

Generally, a color that is in the green-blue-violet range.

Light having a color temperature of approximately 3600�K to 4900�K, i.e., bright-white to blue-white.

1. A loop made of rope attached to a yoke for the purpose of supporting excess coils of electric cable. 2. A round bracket provided on the rear of some luminaires for the purpose of retaining coils of electric cable when the luminaire is to be stored or transported.

Corporate events are any event that highlights an association, organization, or business, rather than an entertainment act

First meeting between the performer and their costume. Enables wardrobe staff to ensure a proper fit, and the performer to see if everything is acceptable.

Lighting that does a particular job during the show

A percussion instrument often used in latin music. Over the last number of years it is used more often in pop music to color the music. You'll often hear the cowbell played with strict quarter notes to lay a rhythmic foundation for the song. The cowbell gets its name from use with a cow. Yep, that's right. It was originally used around the cow's neck so that the owners could keep track of them. The cowbell comes in many different sizes and tones.

The cymbal played that's used for emphasizing a certain beat in the song. This cymbal has more sustain than a ride cymbals does.

An open ended adjustable hand wrench originally produced by the Crescent Tool Co.

A group of people who work on a show

One who is in charge of a crew of workers (i.e. Lighting Crew Chief, Audio Crew Chief)

A rectangular cutting off of image edges.

1. In the theater industry, a bar mounted horizontally on top of a stand. It contains two or more sliding tees for mounting luminaires, and a fixed tee for mounting the bar to the stand. 2. In the film and video industries, a bar mounted horizontally between two stands for the purpose of hanging luminaires or grip equipment.

A relatively slow change from one control console setting to another.

A luminaire used for cross lighting.

Illumination from two sources on opposite sides of the subject.

A set of audio filters designed to restrict and control the range of input signal frequencies which are passed to each loudspeaker drive unit. A typical two-way speaker will employ three filters: a high-pass filter allowing only the higher frequencies to feed the tweeter, a low pass filter that allows only the lower frequencies to feed the woofer, and a second high-pass filter that prevents subsonic signals from damaging the woofer.

The frequency at which one driver ceases to produce most of the sound and a second driver takes over. In the case of a two-way speaker the crossover frequency is usually between 1 and 3kHz.

1. Command given to technical departments to carry out a particular task. 2. Any signal that indicates another action should follow.

1. An event in a production that is the signal for a specific action. 2. The signal given in order to cause such an action. 3. The response to such a signal, which may include a change in intensity settings for a luminaire(s), or a change in action by an apparatus(es).

A light used to signal a cue. Red usually means stand by and green usually means execute the cue.

A system for making one or more separate mixes audible to musicians while performing, recording and overdubbing. May be auditioned via headphones, IEMs or wedge monitors.

Cutting out action and dialogue between cues during a technical rehearsal to save time

The flow of electricity through a circuit, measured in Amperes

1. To remove illumination from a scene or object. 2. To block a portion of a light beam

Also known as data sheet; a paper, pamphlet or leaflet that has detailed information about a lamp, luminaire, piece of equipment, etc., usually supplied by the manufacturer.

The frequency above or below which attenuation begins in a filter circuit.

A concave area generally in the upper right bout of a normal right-hand guitar that allows the player easier access to the high frets.

A general term for anything used to block a portion of a light beam, e. g., flags, cutters, shutters, barn doors, etc.

One complete vibration (from maximum peak, through the negative peak, and back to the maximum again) of a sound source or its electrical equivalent. One cycle per second is expressed as 1 Hertz (Hz)

A vertical surface which is used to form the background for a theatrical type setting, usually made of heavy cloth drawn tight to achieve a smooth, flat surface. It usually represents the sky or suggests limitless space. Traditionally, cycloramas were dome shaped or horizontally curved, but may now also be flat or vertically curved as well.

A copper/bronze (or variation of metal alloy) disk struck with a drumstick to ride or emphasize beats with the hands. Cymbals add texture to the music. They can be crashed (crash cymbal) or ridden during a beat (ride cymbal). Two cymbals can also be played together such as in a marching band or hi-hat cymbals. Of recent, manufacturers are making cymbals with holes in them or with 8 sides (octagon cymbal) for varying effects.

A form of audio-over-IP (layer 3) created by Australian company�Audinate in 2006. DANTE is an abbreviation of 'Digital Audio Network Through Ethernet'. The format provides low-latency multichannel audio over standard ethernet intrastructures. it has been widely adopted in the broadcast, music studio, and live sound sectors.�

An acronym for Digital Audio Tape. Developed by Sony in 1987, it looks similar to an analogue audio cassette but contains professional quality digital information. It is capable of high fidelity music reproduction.

An abbreviation of Digital Audio Tape, but often used to refer to DAT recorders (more correctly known as R-DAT because they use a rotating head similar to a video recorder). Digital recorders using fixed or stationary heads (such as DCC) are known as S-DAT machines.

A unit of measurement for Voltage Potential, specifically for direct current voltages.

Digitally Controlled Oscillator. Used in digitally-controlled synthesizers.

Direct Injection, or Direct Instrument Box. A device which accepts the signal input from a guitar, bass, or keyboard and conditions it to conform to the requirements of a microphone signal at the output. The output is a mic-level, balanced signal with a low source impedance, capable of driving long mic cables. There is usually a facility to break the ground continuity between mic cable and source to avoid unwanted ground loop noises. Both active and passive versions are available, the former requiring power from internal batteries or phantom power via the mic cable. Active DI boxes generally have higher input impedances than passive types and are generally considered to sound better.

Digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor

A somewhat unique digital multiplex signal with specific characteristics that is commonly used in the stage and studio lighting industries. Control consoles designed to generate this signal were originally designed to control a maximum of 512 apparatuses, usually dimmers, but now can control many more.

Lighting control accessory which accepts multiple DMX inputs (e.g. from a number of lighting controllers) and merges them together to a single DMX feed to control dimmers or moving lights etc.

A DMX terminator is a 3 or 5 pin XLR connector which is used at the end of a DMX run to absorb the data signal to stop it being reflected back along the DMX cable. The terminator is very easy to make, and consists of a 120 Ohm half-watt resistor soldered between pins 2 and 3 of the XLR connector. A DMX run should always be terminated, and although the system may work without one, continued operation cannot be guaranteed. A system with poor quality DMX cable (or cable of a long run) will require termination in order to operate correctly.

Dots Per Inch. A measure of the resolution of a printed or computer image

Digital Video. Professional video format

An acronym for "Digital Versatile Disk". It is the same size as a compact disc (CD). A single-layer DVD has a storage capacity of 4.7�GB and a dual-layer disc has a capacity of 8.5�GB.

An arrangement of sharing a common data signal between multiple devices. A �daisy chain� is created by connecting the appropriate output (or through) port of one device to the input of the next. This configuration is often used for connecting multiple MIDI instruments together: the MIDI Out of the master device is connected to the MIDI In of the first slave, then the MIDI Thru of the first slave is connected to the MIDI In of the second slave, and so on... A similar arrangement is often used to share a master word clock sample synchronising signal between digital devices.

The control of a resonant device. In the context of reverberation, damping refers to the rate at which the reverberant energy is absorbed by the various surfaces in the environment. In the context of a loudspeaker it relates to the cabinet design and internal acoustic absorbers.

Venue has been closed to the public

Light that has a color temperature of approximately 5500-5600�K, which has been approximated to be the color temperature of ordinary sunlight during the day under normal atmospheric conditions.

A filter used to balance light from a source such that the spectral distribution will approximate daylight, i.e. 5500-5600�K.

A device for reducing the effect of sibilance in vocal signals.

The process of removing lights and cables from grid, returning the venue to its normal state

Anything that is supposed to be carrying, or has the potential to carry electrical current, but isn't.

A rigging point direct to the grid/beams in the air

A static suspension without any lifting power

This is a handle that has to be squeezed by a technician in order for a pre-programmed automation sequence to take place. If for any reason the relevant technician is not in position, the system does not allow the sequence to run.

A muted note played with no discernible pitch.

The progressive reduction in amplitude of a sound or electrical signal over time, eg. The reverb decay of a room. In the context of an ADSR envelope shaper, the Decay phase starts as soon as the Attack phase has reached its maximum level.

A form of �spaced microphone� arrangement in which three microphone capsules (usually, but not always, with omnidirectional polar patterns) are placed in a large triangular array roughly two metres wide, with the central microphone one metre further forward. Sounds approaching from different directions arrive at each capsule at different times and with slightly different levels, and these timing and level differences are used to convey the directional information in the recording. The timing differences between channels can result in unwanted colouration if they are combined to produce a mono mix.

The deciBel is a method of expressing the ratio between two quantities in a logarithmic fashion. Used when describing audio signal amplitudes because the logarithmic nature matches the logarithmic character of the human sense of hearing. The dB is used when comparing one signal level against another (such as the input and output levels of an amplifier or filter). When the two signal amplitudes are the same, the decibel value is 0dB. If one signal has twice the amplitude of the other the decibel value is +6dB, and if half the size it is -6dB.

Device used to recover the component signals from a composite (encoded) source. Decoders are used in displays and in various processing hardware where components signals are required from a composite source such as composite chroma keying or color correction equipment.�

A device intended to prevent the transmission of physical vibration over a specific frequency range, such as a rubber or foam block.

Reduction of income that is able to be taxed and is commonly the result of expenses; particularly those incurred to produce additional income

The aggregate of fine details available on-screen. The higher the definition of an image, the greater the number of details [that can be discerned by the human eye or displayed]. During video recording and subsequent playback, several factors can conspire to cause a loss of definition. Among these are the limited frequency response of magnetic tapes and signal losses associated with electronic circuitry employed in the recording process. These losses occur because fine details appear in the highest frequency region of a video signal and this portion is usually the first casualty of signal degradation. Each additional generation of a videotape results in fewer and fewer fine details as losses are accumulated

The time between a sound or control signal being generated and it auditioned or taking effect, measured in seconds. Often referred to as latency in the context of computer audio interfaces.

Federal agency which controls the transport of all hazardous materials including fireworks. This organization also assigns all legal commercial fireworks with an EX Number.

The in-focus range of a lens or optical system around an item of interest. It is measured from the distance behind an object of interest, to the distance in front of the object of interest, when the viewing lens is specifically focused on the object of interest. Depth of field depends on subject-to-camera distance, focal length of the lens, and f-stop.

The range of sensor-to-lens distance for which the image formed by the lens is clearly focused.

An alternative term for mixer

The movable membrane in a microphone capsule which responds mechanically to variations in the pressure or pressure gradient of sound waves. The mechanical diaphragm vibrations are converted into an electrical signal usually through electromagnetic or electrostatic techniques such as ribbon, moving coil, capacitor or electret devices.

Glass colour filters which reflect all light except that which is the colour of the filter, which passes through. Normal plastic gels absorb the unwanted colours, turning the light into heat. Dichroic filters run cooler, and produce a much cooler beam of light. Longer lasting, but a lot more expensive, they are predominantly used in moving lights or architectural applications.

A low voltage display lamp with a reflector that lets heat pass through it, rather than reflecting it. Results in a much 'cooler' light.

1. To scatter light using diffusion material. 2. A term used to describe a somewhat dull and/or stippled surface that is moderately reflective.

Generally, something made of diffusion material.

An apparatus used to hold diffusion material. It can be of various shapes and sizes, and may comprise one or more pieces.

Any reflecting or transmitting media for which the reflected or transmitted light is distributed uniformly, i.e., scattered over a wide range.

Many electronic devices use digital logic. Information is handled in separate bits (either ON or OFF) rather than continuously variable analogue signals. Most computer lighting boards give a digital multiplexed output, and more and more sound equipment is going digital.

A means of representing information (eg audio or video signals) in the form of binary codes comprising strings of 1s and 0s, or their electrical or physical equivalents. Digital audio circuitry uses discrete voltages or currents to represent the audio signal at specific moments in time (samples). A properly engineered digital system has infinite resolution, the same as an analogue system, but the audio bandwidth is restricted by the sample rate, and the signal-noise ratio (or dynamic range) is restricted by the word-length.

�A term first used in the 1980s to describe early �tapeless� recording/sampling machines like the Fairlight and Synclavier. Nowadays, DAW is more commonly used to describe Audio+MIDI �virtual studio� software programs such as Cubase, Logic Pro, Digital Performer, Sonar and such-like. Essentially elaborate software running on a bespoke or generic computer platform which is designed to replicate the processes involved in recording, replaying, mixing and processing real or virtual audio signals. Many modern DAWs incorporate MIDI sequencing facilities as well as audio manipulation, a range of effects and sound generation.

A digital processor that generates delay and echo effects.

The new generation of dimmers that can respond directly to the digital multiplexed output of the lighting desk. The technology also permits the dimmer to report faults and other data back to the control board.

Video technology that is used for front and rear projection units

A system that simultaneously transmits more than one digital signal.

�An electronic signal where every different value from the real-life excitation (sound, light) has a different value of binary combinations (words) that represent the analog signal

When applied to video cameras, DSP means that the analog signal from the CCD sensors is converted to a�digital signal. It is then processed for signal separation, bandwidth settings and signal adjustments. After processing, the video signal either remains in the digital domain for recording by a DVR or is converted back into an analog signal for recording or transmission. DSP is also used in other parts of the video chain, including DVRs, and switching and routing devices

A powerful microchip used to process digital signals.

A method of decreasing the apparent angle of view of a digital photographic or video image

An apparatus that converts digital signals to analog signals.

Converting analog audio and/or video into digital form.

Video connection that converts the digital signal to an analog signal

1. To change the intensity of a luminaire. 2. The state of a luminaire at very low intensity

The quality of a chord having its intervals as the 1st, flat 3rd and flat 5th of the major scale.

An apparatus used to control the intensity of a luminaire.

1. The area where the dimmer racks are located 2. Where the lighting guys hang out

A circuit board that contains some or all of the electronic components needed to electronically dim a luminaire.

A discrete apparatus that contains a dimmer card, its enclosure or mounting apparatus, and perhaps other related items such pilot lights or handles.

A portable housing that contains a group of electronic dimmers, usually not less than 4 or more than 24. Some dimmer packs are designed such that they can be permanently installed.

An apparatus, usually 19" long, that contains a group of electronic dimmers that get installed into a dimmer rack.

An apparatus designed to contain a large group of electronic dimmers. Permanently installed dimmer racks comprise a metal frame and housing in their construction, and are hard wired. Portable dimmer racks are provided with connectors for a tie-in, and are usually provided with wheels, handles, and a metal frame in a metal-lined wooden housing.

On touring productions, repsonsible for monitoring the portable dimmer racks and power distribution to all lighting and show control systems

A means of connecting two electrical circuits so that both AC and DC signals may be passed between them.

An electrical current that maintains constant direction.

The form of electrical current supplied by batteries and the power supplies inside electrical equipment. The current flows in one direction only.

A voltage that maintains constant polarity.

Illumination on a subject or area that goes directly from the front of the luminaire in a straight line to the subject or area.

The act who takes the stage directly before the headliner.

A footlight mounted into a stage floor, that when closed, has its lid completely flush with the floor. The lid is usually made from the same material as the stage floor.

Used to describe vinyl discs, CDs and MiniDiscs.

The area immediately surrounding the fireworks mortars used for an outdoor fireworks display.

An abbreviation of Diskette, but now used to describe computer floppy, hard and removable data storage disks.

The ultimate image presented to a viewer; the process of presenting that image

(formerly known as special fireworks) Large fireworks articles designed to produce visible or audible effects for entertainment purposes by combustion, deflagration, or detonation.

The immediate area where a fireworks display is conducted, including the discharge site, the fallout area, and the required separation distance from mortars to spectator viewing areas, but not spectator viewing areas or vehicle parking areas.

The deviation of the received signal waveform from that of the original transmitted waveform.

A system whereby low-level noise equivalent to one quantising level is combined with a digitised audio signal in such a way as to perfectly linearise the digital system. Dither must be employed whenever the wordlength is reduced, otherwise quantising distortion errors will manifest.

Originating from West Africa, this goblet shaped drum is most often rope-tensioned and had become one of the more common percussion instruments in the western hemisphere over recent years.

A short piece of steel wire rope. Usually between 1-2 feet

A specific shape of drive unit diaphragm intended to push and pull the air to create acoustic sound waves. Most tweeters use dome-shaped diaphragms which are driven around the circumference by the drive unit�s motor system. �Soft-domes� are made of a fabric � often silk � while metal domes are constructed from a light metal like aluminium, or some form of metal alloy.

A flat metal apparatus with a circular hole in the center used to reduce halation and sharpen the image when using patterns.

When the venue opens to the public. For example "Doors are at 6pm tonight".

The largest and lowest-pitched instrument of the violin family, providing the bassline of the orcestral string section

The use of two bass drums with a drum set. Double bass drumming can also be played with a twin pedal or double bass pedal and just one bass drum.

A twin pedal that strikes both beaters on the same bass drum.

A somewhat elongated lamp that has a base and contact on each end.

Two pipe clamps connected together via a short stud with their serrated jaws on opposite ends. It is used to connect two pipes together.

Two notes played simultaneously.

1. Downward illumination, almost perpendicular with the floor. 2. A luminaire that provides such illumination.

The "main" pulse as it relates to the rest of the measure. If you have 8 eighth notes in a bar of 4/4 time, beats 1, 2, 3 and 4 would be considered the downbeat. The "and" of 1, "and" of 2, "and" of 3, and "and" of 4 would be the upbeat.

The stage area nearest the audience, also containing the apron.

A translucent mask with traceable patterned cutouts of luminaires and other items used to draw a light plot.

To arrange electric cables in a neat and orderly fashion.

A full rehearsal, with all technical and creative elements brought together. The performance as it will be 'on the night'.

Rooms containing clothing and mirrors where performers change into their constumes and apply makeup

A physical device designed to generate an acoustic sound wave in response to an electrical input signal. Drive units can be designed to reproduce almost the full audio spectrum, but most are optimised to reproduce a restricted portion, such as a bass unit (woofer) or high-frequency unit (tweeter). A range of technologies are employed, with most being moving-coil units, but ribbon and electrostatic drive units also exist, each with a different balance of advantages and disadvantages.

A specially made hi hat clutch that allows the top cymbal to drop when you hit a lever on the side of it. This drum accessory is for use with double bass drumming.

The shackle that is screwed in use in a basket.

The vertical wire rope for rigging or suspending an object from a rigging point

An iris mounted to a plate that can be installed, i.e., dropped into or removed from a luminaire.

A sudden brief loss of signal level. In�analogue recording tape this is often caused by a defect in the oxide layer caused by damage (eg. creasing) or by a temporary clogging of the replay head, and typically affects the high-frequencies most. The effect is less likely and less noticable with wider and faster tape formats.

The practice of lowering the sixth string (E) by a whole tone, one octave lower than the fourth string.

A hollow cylindrical shell of any size that has a head stretched over one or both ends and is beaten with the hands or a stick. There are also electronic drums where no shell is needed, just a triggering pad. When struck, it triggers synthesized sounds of all types.

The central electronic guts or "brain" of a standard electronic drumset. This brain houses the sound sources and controls drum sensitivity, tempo, drum beats, drum patterns, and songs.

A "filler" or phrase to be played between different sections of a song. A drum fill can be as simple as a couple of tom tom hits or a blistering, machine gun-like burst of notes. Drum fills can range from 1 beat to 8 measures (or more) in length.

The covering or membrane that stretches over the drum to produce it's sound. Drumheads are made of animal skin and synthetic plastics.

A small "T" shaped wrench (usually metal, although sometimes plastic), that tightens or loosens the drum.

A section comprised of only drums and percussion.

A synthetic playing surface which produces electronic trigger signals in response to being hit with drum sticks.

A large metal frame that surrounds the drumset and holds cymbal stands, tom attachments, and percussion accessories. This setup allows for greater memory lock and is very practical. The downside is that it is heavy and usually bulky.

A set of drums consisting of generally 4 to 5 drums or more. 5 piece drumsets are most common but it often depends on the drummer's preference and/or the style of the music being played. For example, combo jazz drummers generally play a small 3 or 4 piece drumset. Drummers play the drumset (or drum kit) sitting down on a drum seat (or throne). A drumset comprises more than just the drums. It can also include timbales, cowbells, wood blocks, chimes or any number of percussion instruments. The number used when referring to a drumset (for example: 5 piece drumset), refers to the drums themselves, not the individual parts. So, on a 5 piece drumset, you wil have only 5 drums but you could have as many as 20 different pieces or parts to the drumset. In the earlier days of drumming, the drumset was called a trapset.

A rhythmic break in the song where the drummer gets to shine. Ala "Wipeout".

A pair of sticks used to play a drum or set of drums. Popular models of drumsticks for drumset are ProMark, Vic Firth, and Vater.

One who sets up and maintains a drum set (or set up) for another drummer. Usually famous drummers or those that play with name bands have their own drum tech. A drum tech is usually very knowledgeable about drums and can tune and tweak them to their maximum sound potential.

A drummer is one who plays the drum or drums (duh).

Frozen solid carbon dioxide (CO2) at a temperature of -78.5� centigrade which produces clouds of steam-loaded CO2�gas forming a low-lying mist or fog when dropped into boiling water. Although non-toxic, caution is required in the storage and handling of dry ice because of its extreme cold. Water is boiled in a large tank offstage, into which the dry ice is lowered in a basket. Fans and ducts then direct the gas onto the stage. Dry ice does not support life, so care should be taken that small animals, actors etc.are not below the level of the dry ice for more than a few seconds.

The practice of transferring material from one medium to another, or of adding further material to an existing recording

A system for controlling the level of one audio signal with another. For example, in a broadcast radio context a music track can be made to 'duck' or reduce in volume whenever there's a voice over.

Any device in which the fuse or igniter fails to ignite the main pyrotechnic charge. The term, dud, is reported to have originated as an acronym for dangerous unexploded device.

To transfer digital data from one device to another. A SysEx dump is a means of transmitting information about a particular instrument or module over MIDI, and may be used to store sound patches, parameter settings and so on.

An opaque material used for butterflies, cutters, flags, gobos, and overheads in the film and video industries.

Employs powered lifting equipment that magnifies the loading on the supporting equipment and structure due to the need to overcome the force of gravity

A type of microphone that works on the electric generator principle, such as moving Coil and ribbon mics. An acoustical sound waves impact the microphone diaphragm which then moves an electrical conductor within a magnetic field to generate a current, the amplitude and polarity of which reflects the acoustic signal.

The amplitude range, usually expressed in decibels, between the loudest signal that can be handled by a piece of equipment and the level at which small signals disappear into the noise floor.

The difference between the maximum acceptable signal level and the minimum acceptable signal level.

One that will absorb energy by stretching

Playing soft to loud on the drums.

A way of describing the relative levels within a piece of music.

The identification number assigned by DOT to a commercial fireworks device. All legal commercial fireworks must have an EX number.

The initial sound reflections from walls, floors and ceilings following a sound created in an acoustically reflective environment.

The standard household male, parallel blade connector that may or may not have a ground pin.

A treatment applied to an audio signal in order to change or enhance it in some creative way. Effects often involve the use of delays, and include such treatments as reverb and echo.

A cymbal that is non-traditional in sound such as a gong cymbal, pang cymbal, or splash cymbal. Used sparingly for special accents and unique effects.

�An interface system, usually involving separate send and receive connections, which allows an external signal processor to be connected into the audio chain

A special, lensed luminaire designed to project images by placing one or more glass, film, or plastic slides or metal patterns into its beam. The first crude effects projector was developed by Steele MacKay in the late 1880's.

An additional dedicated mixer input channel, usually with minimal facilities, designed to accommodate the output from an effects unit.

A square or rectangular, partitioned apparatus that, when installed on large open face luminaires, reduces glare.

A term used by professional film and video industry people to refer to those operating or utilizing luminaires and related equipment, such as cable, distribution equipment, dimmers, etc.

A device that provides and controls the electric current used to ignite fireworks during a display.

The cycles per second of alternating current, in Hertz. In North America, and parts of South America and South East Asia, the frequency is 60 Hz. The rest of the world operates at a frequency of 50 Hz.

A technique used to ignite fireworks using a source of electric current.

An Electro-Explosive Device (EED) that is used to remotely initiate other pyrotechnic devices by means of an electrical current.

A general term for an unwanted electronic disturbance in conductors or electrical or electronic equipment. This equipment can also be the cause of electrical noise.

Anything that has the potential to provide voltage and electrical current, i.e., electrical power.

1. Generally, one versed in the field of electricity and its application. 2. A term used by professional stage lighting people to refer to those operating or utilizing luminaires and related equipment, such as stage cable, dimmers, etc.

A catch-all term used to describe any type of power distribution equipment hung from or attached to an electrics pipe.

The opposite of electronic drums. Drums that are synthesized. They work off of electricity and use a sound source or brain module. Common electronic drums companies are Pintech, Roland and Hart Dynamics.

A working drawing usually drawn to scale, showing the side view of a set or lighting rig.

A reflector designed to converge light rays to a single point, except that point which is occupied by the point source, eventually resulting in a beam that varies in width, depending on the distance between the two points. It has the shape of the end section�of an ellipsoid

Name for a type of stage lighting instrument used to collect and direct the light through a barrel that contains a lens or lens train

A spotlight that embodies an ellipsoidal reflector and framing shutters, and sometimes an iris and pattern slot.

All scenic automation or powered flying systems have an emergency stop facility built into them. The pressing of any e-stop button in the system will immediately halt any movement and prevent any further movement until the system is reset.�

An audio processor designed to brighten audio material using techniques such as dynamic equalisation, phase shifting and harmonic generation.

The way in which the amplitude of a sound signal varies over time.

An electronic circuit capable of generating a control signal which represents the envelope of the sound you want to recreate. This may then be used to control the amplitude of an oscillator or other sound source, though envelopes may also be used to control filter or modulation settings. The most common example is the ADSR generator.

An electronic circuit that introduces compensation for frequency discriminative effects of elements within the television system, particularly long coaxial transmission systems.

A device which allows the user to adjust the tonality of a sound source by boosting or attenuating a specific range of frequencies. Equalisers are available in the form of shelf equalisers, parametric equalisers and graphic equalisers � or as a combination of these basic forms.

Periodic advance payment of taxes based on the amount of income that is earned and the amount of estimated tax in that period

A system for connecting a number of computer systems to form a local area network

A field that has a relatively uniform decrease in intensity as viewed from the center to the edge of the field, i.e., a field that does not have a noticeable hot spot.

In MIDI terms, an event is a single unit of MIDI data, such as a note being turned on or off, a piece of controller information, a program change, and so on.

The outer glass part of a lamp.

A device designed to increase the dynamic range, typically by reducing the volume of low level signals (below a set threshold), or to increase the volume of high level signals

The cost requred for something; the money spent on something

Any material that is capable of undergoing a self-contained and self-sustained exothermic chemical reaction at a rate that is sufficient to produce substantial pressures on their surroundings, thus causing physical damage. Explosives fall into 2 classes, detonating and deflagerating.

Any chemical compound or mixture, the primary purpose of which is to function by explosion, producing an audible effect.

The amount of light per unit area

A catch-all term used to describe any item that stretches the reach of, or increase the length of something, e. g., side arms, extension arms, stage cables, etc.

The fresnel lens of a frenel spotlight

The F shaped opening in the sound board of some guitars, usually archtops or resonators.

The speed or ability of a lens to pass light. It is calculated by dividing the focal length of the lens by its diameter. The f-stop also is a factor in more areas of focus in the image known as Depth of Field.

A rating often applied to scrims used in the film and video industries on the ability to dim light. This rating is directly related to a camera's ability to allow for the admittance of light.

Short for Effects

When a shot gradually fades to a single color, usually black or white

To gradually increase or decrease the intensity of light.

The gradual increase in intensity of light.

The gradual decrease in intensity of light.

On computerised memory lighting control desks, a lighting fade can have two times - an up fade and a down fade. The Up fade time refers to the time it takes dimmer levels to rise to their new positions. The Down fade time refers to the time for dimmer levels falling to their new positions.

To gradually decrease the intensity of all lighting to a blackout.

A sliding potentiometer control used in mixers and other processors.

An item found on most control consoles, such as a slider, used to fade.

The designated area in which hazardous debris is intended to fall after a pyrotechnic device is fired.

A common problem among lighting & sound operators, when two buttons are accidentally pressed at the same time by a finger that's too large for the buttons.�

A thick 2 and 4, slightly behind the beat backbeat with a lot of soul. Common in funk and blues drumming.

A power supply or signal supply to a piece of equipment or installation

Special kind of positive loop gain which occurs when a sound loop exists between an audio input (microphone) and an audio output (loudspeaker)

Process by which information about the position of a piece of scenery is fed back into an automation system to ensure it's running correctly.

A set of electric cables, usually individually insulated conductors with a high ampacity, used to remotely connect portable dimmer racks, power distribution racks, and the like, to the electrical supply. They are usually of the wire types W or SC, and are often provided with Cam-lok connectors.

A term applied to a connector that contains the holes and/or slots for receiving the pins, prongs, blades and/or tabs of a male connector. The female connector should always be attached to the line side of a circuit.

The metal sleeve used to form an eye termination in sttel wire rope which is pressed onto the rope under pressure from a hydraulic tool

An organized series of concerts, typically held outdoors, sometimes held annually in the same place

Manage the behind-the-scenes logistics of the festival by working with vendors, city officials, and on-site staff

The technology of transferring information, e.g., in communications or computer technology, through thin flexible glass or plastic tubes of optical fibers using modulated light waves

1. A method of directing light down a very thin glass fibre. Fibre Optics are used mostly in communication, but find theatre applications in star cloths which are black backcloths with the ends of optical fibres poked through, to create a mass of pin pricks of light. A large bundle or harness of fibres may be fed from one light source, sometimes with a motorised colour or flicker wheel. 2. New technology enables digital sound signals to be sent down optical fibres, replacing heavy and expensive multicore cables.

The accuracy or precision of a reproduced acoustic sound wave when compared to the electrical input signal.

In Photometry, the circular area of the base of a cone shaped beam where the intensity is at least 10% of the maximum intensity. The maximum intensity is ideally located at the center of the base. It should be noted that some luminaires, such as ellipsoidal spotlights and follow spots, can be adjusted or designed such that the light emanating from them does not include the entire field, i.e., the edge of the beam is greater than 10% of its center.

The angle of the vertex of a cone shaped beam where the perimeter of the base is defined by where the intensity is 10% of the maximum intensity.

The diameter of the base of a cone shaped beam where the perimeter of the base is defined by where the intensity is 10% of the maximum intensity.

The maximum angle of view that can be seen through a lens.

Describes the polar response of a microphone or loudspeaker that is equally sensitive both front and rear, yet rejects sounds coming from the sides. Also called Bipolar.

The wire inside an incandescent lamp envelope that glows and emits light when heated, i.e., when electricity passes through it.

To create the illumination needed to reduce shadows in an area or on a subject.

1. Supplementary illumination used to reduce shadows, preventing them from appearing black. 2. A luminaire that provides such illumination.

A term that refers to color media, diffusion material, or neutral density filters.

An electronic circuit designed to attenuate a specific range of frequencies.�

1. Apple video editing software. 2. The final finished edit of a film/video program in which the director and producer has approved

A rapidly fired sequence (barrage) of aerial fireworks, typically fired at the end of a display.

Banjo-style picks that fingerstyle guitarists use when playing steel-string instruments.

Playing with the fingernails or fingertips with or without fingerpicks as opposed to playing with a flatpick.

A pattern-based way of playing through chord progressions using the fingers.

To ignite pyrotechnics by using an electric match, electrical current, or some other means.

A portable device that discharges a jet of water, foam, gas, or other material to extinguish a fire

An official who is responsible for enforcing fire regulations or investigating fires

To switch on a luminaire or some other electrical apparatus.

A computer interface format based upon the IEEE 1394 standard and named FireWire by Apple computers (Sony�s i.Link format is also the same interface). FireWire is a serial interface used for high speed isochronous data transfer, including audio and video. FireWire 400 (IEEE 1394-1995 and IEEE 1394a-2000) or S400 interface transfers data at up to 400Mb/s and can operate over cables up to 4.5metres in length. The standard �alpha� connector is available in four and six-connector versions, the latter able to provide power (up to 25V and 8 watts). The FireWire 800 format (IEEE 1394b-2002) or S800 interface uses a 9-wire �beta� connector and can convey data at up to 800Mb/s.

Any composition or device for the purpose of producing a visible or an audible effect by combustion, deflagration, or detonation, and that meets the definition of consumer fireworks or display fireworks.

Individual who actually ignites fireworks devices at a show.

A term used to describe an optical system whereby the lenses in a luminaire remain at a fixed distance from one another, although they may move as a group within the system.

An optical system where the lens or lenses in a luminaire remain stationary, i.e., they lack the ability to move.

A term that is often used interchangeably with Luminaire.

This Pyrotechnic device often utilizes a smokeless powder based composition and produces a rising column or rolling ball of fire in various colors. This device produces very little smoke and minimal debris. Duration of the effect is based on the quantity of composition loaded, the particulate size of the composition, and the diameter of the tube. Typical duration does not exceed 5 seconds. This is a pyrotechnic device not to be confused with other flame effects using gaseous or liquid combustible substances. This effect can be prepackaged in a tube or can 1 inch to 4 inches (25mm to 102mm) in diameter or packaged in other types of containers. In addition, this device can be assembled on site using an appropriate mortar or containment device.

An effect which combines a modulated delay with the original signal, using feedback to create a dramatic, sweeping sound.

A cylindrical tube device, which contains a pressed pyrotechnic composition. Upon ignition, the device produces a bright flame in various colors and durations. Typically stage flares range from 2� to 6� (50mm to 152mm) in length and �� to 1� (13mm to 25mm) in diameter. Effect duration is typically from several seconds up to 60 seconds or longer.

A small box containing the socket into which a pyro cartridge is plugged. Also known as a flash pod or firing pod.

A push switch on a lighting desk which flashes selected channels / memories / submasters to full (100%) while pressed. Some Flash buttons on submasters can be set to latch (ie they stay on when pushed, until they are pushed again).

A large capacity solid-state memory configured to work like a conventional hard drive. Used in digital cameras and audio recorders in formats such as SD and CF2 cards, as well as in �pen drives� or �USB memory sticks�. Some computers are now available with solid state flash drives instead of normal internal hard drives.

Method of checking whether lanterns are functioning properly by flashing them on one at a time. It is good practice to flash lanterns to 70%, rather than Full to preserve lamp life.

These are different forms of nitrated cotton (cellulose nitrate, nitrocellulose). The material is stored and transported either wet with water or alcohol. These materials burn rapidly when ignited with very little smoke or ash. Uses include magician hand flashes, ignition of ice fountains and various other pyrotechnic effects.

A generic term for a pyrotechnic device consisting of a small cylindrical containter into which prytechnic powder has been loaded. At the bottom of the container is an electric match which, when a large enough current flows through it, produces a spark which ignites the powder

Mixtures which contain powdered aluminum or a magnesium/aluminum alloy which, when ignited, can result in a violent explosion and flash.

Typically a preloaded cylindrical cardboard tube 6� to 18� (152mm to 457mm) in length with a longitudinal slit cut from end plug to the opposing end plug. Inside the tube is a pyrotechnic composition that, upon ignition, produces a fan pattern flash and or spray of sparks and/or stars. The effect pattern produced, while wide in the side-to-side axis, is very narrow and controlled in the front to back axis. Duration of the effect is short and does not usually exceed 1.5 seconds

A triangular or teardrop-shaped piece of nylon or plastic used to pluck or strum guitar strings. Flatpicks are available in a large variety of shapes, sizes, and thickness.

Steel strings which use flat ribbon winding rather than round wire for the thicker strings. Preferred by jazz guitarists.

The strobing of some luminaires that cannot be visually detected because of the frequency of its output voltage, but can adversely affect the way motion picture film records light.

A term used to describe electronic ballasts that electronically alter the electrical frequency that causes flicker.

The space above a stage where scenery, luminaires, etc. are hoisted above horizontal sight lines.

Metal or hard case framed wooden box on wheels with a removable lid used for transporting equipment between venues. Flightcases are very strong, and have reinforced corners and edges. Care should be taken when lifting flightcases as they can be very heavy.

1. The position of a movable lamp, lens, or pair of lenses on a spotlight that produces the widest field angle. 2. To direct a large amount of light on a relatively large area.

A luminaire consisting of a reflector, lamp, and sometimes a single lens, used to direct a large amount of light on a relatively large area.

A stage pocket whose cover is flush mounted with the floor to which it is mounted.

The deepest tom (generally) on a standard drum set. It sits upright on 3 legs. In the last 20 years drummers have also mounted their floor toms on cymbal stands.

The property of certain materials to absorb radiation of certain wavelengths, usually ultraviolet, and re-emit the radiation as light.

A lamp that uses fluorescence as its light source.

A term used to describe anything whose upper surface, when installed, is flush with the surface to which it was installed. This term is used to describe floor and wall pockets, disappearing footlights, ceiling ports, and certain types of connectors.

To lift scenery, truss, luminaires, etc., into the air by support cables, chain, or ropes, with the aid of motors, pulleys, winches, and the like.

In modern theaters, it is a sturdy, steel structure with an assortment of pulleys and counterweights, and cam-like clamps or clutch mechanisms which secure the ropes that support the battens and electrics pipes. These apparatuses are often motorized.

The support structure mounted to the stage wall that contains the ropes or cables and pulleys that go between the flies and the flyrail or pinrail.

A polystyrene, styrofoam material used as a substrate for some reflector boards, effective because of its light weight and ease of mounting via reflector forks.

The distance between a particular point of a lens or reflector, and the focal point.

The distance from the focal point to the principal point of the lens. The focal length is usually measured in millimeters of the lens. Focal length is an indication of the lens capability to capture a wide angle of view or a narrow view of objects that are far away (telephoto).

The plane that is perpendicular to the axis of an optical system and also contains the focal point.

The point at which a lens or mirror will focus parallel incident radiation.

The small region where a lens or reflector concentrates the light from a light source.

1. To aim and adjust a luminaire to give the beam its desired size (spot or flood), edge (soft or hard), field (even or peak), and/or shape (round, patterned, or cut). 2. To aim and adjust a lens, pair of lenses, light source, reflector, or any combination of these so that the light is concentrated at the focal point.

Finding a point where the subject is clear

Documentation produced by the lighting designer which shows graphically the exact focus of a particular lantern in the rig. Essential for long-running shows where the crew can use it as a reference when replacing lanterns or checking focus after cleaning etc. The charts can also be used to do a 'rough' focus before a lighting designer arrives at the venue. Touring shows sometimes use a floorcloth marked out with focus information to aid speedy focussing in a new venue.

A movable lens in a multi-lens optical system that adjusts the focus of a luminaire.

The ratio of spot focus to flood focus.

A system for making one or more separate mixes audible to musicians while performing, recording and overdubbing. Also known as a Cue mix. May be auditioned via headphones, IEMs�or wedge monitors.

A narrow-beam focusing instrument that is manually operated, and usually comprises a powerful light source, an iris, shutters, a color changer, and perhaps other features. It is usually operated from an adjustable stand and is used to follow performer(s) on a stage with its beam, surrounding the performer(s) in a large pool of light.

The very front of the stage.

The accessory that depresses the bass drum or hi-hat cymbals.

A non-metric unit of measurement for Illumination, i.e., 1 lumen per square foot.

A luminaire, often a striplight, that is used from the floor of a stage, runway, or other performing area. This luminaire received its name because it was originally used to illuminate the feet of dancing performers on stage.

A small adjustable stool used to raise the height of the guitar.

The frequency components or resonances of an instrument or voice sound that doesn't change with the pitch of the note being played or sung. For example, the body resonance of an acoustic guitar remains constant, regardless of the note being played.

A procedure required to ready a computer disk or digital tape for use. Formatting organises the medium into a series of �electronic pigeon holes� into which data can be stored. Different computers often use different formatting systems.

Device that projects a spray of sparks.

The process by which the available space on a disk drive gets split up into small, sometimes unusable, sections due to the storing and erasing of files.

The total area, occupied by the television picture, which is scanned while the picture signal is not blanked.

The rate at which frames of video data are scanned on the screen. In an NTSC system, the frame rate is 29.97 frames per second. For PAL, the frame rate is 25 frames per second.

A spotlight that has framing shutters.

Thin, movable, heat-resistant metal plates that are introduced into a beam such that a portion(s) of the beam is blocked off, i.e., framed, affecting the beam pattern, usually forming a sharp edge in the beam. They are used in various types of luminaires, but extensively in ellipsoidal spotlights, usually 4 (top, bottom, right, and left), and follow spots, usually 2 (top and bottom), always situated internally, and usually at the aperture. Framing shutters generally can be independently adjusted, but those used in follow spots usually move simultaneously with a single control mechanism.

Working for different companies at different times rather than being permanently employed by one company

The speed at which something pulses or cycles.

The number of complete cycles of a repetitive waveform that occur in 1 second. A waveform which repeats once per second has a frequency of 1Hz (Hertz).

The variation in amplitude relative to the signal frequency. A measurement of the frequency range that can be handled by a specific piece of electrical equipment or loudspeaker.

A spotlight employing a single fresnel lens that produces a soft edged beam, and usually provided with a spherical reflector and a means to adjust the focus from spot to flood.

The wire inset on fret board; also describes the distance between notes on the fretboard.

The fretted surface of the neck where you do the playing, sometimes known as the fingerboard

1. Illumination from the general direction of the viewer(s). 2. A luminaire that provides such illumination.

Every part of the venue in front of the stage.

Mixes audio for the audience, most often operating from the middle of the crowd. The outpot from the FOH console connects to the Public Address (PA) system

The complete area of the theater in front of the stage, i.e., the audience area.

A term used to describe a lamp whose envelope has been stippled to the point of being translucent for the purpose of diffusing the light. A type of colorless diffusion material made of glass fibers or high-temperature plastic.

The lowest frequency component in a harmonically complex sound.�

Protective device for electrical equipment (E.g. dimmers). The fuse link will melt when excess current flows, preventing damage to people or equipment. Every piece of electrical equipment has at least one fuse in its associated circuit.

A spanset with a metal wire running through it instead of a nylon core. Galvanized Aircraft Cable

A term used by professional film and video industry lighting people to refer to someone overseeing those operating or utilizing luminaires and related equipment, such as electric cables, dimmers, etc.

Ubiquitous sticky cloth tape. Most common widths are .5 inch for marking out areas and 2 inch (usually black) for everything else. Used for temporarily securing almost anything. Should not be used on coiled cables or equipment. Originally known as Gaffer's Tape, from the Gaffer (Master Electrician) on a film set. Also known as Duct Tape. See PVC Tape.

The amount by which a circuit amplifies a signal, normally denoted in decibels.

The act of optimising the signal�level�through each audio device in a signal chain, or through each section of a mixing console, to maintain an�appropriate amount of headroom and keep the signal well above the system noise floor.

A numerical value, or the degree of contrast in a video picture, which is the exponent of that power law which is used to approximate the curve of output magnitude versus input magnitude over the region of interest. Since picture monitors have a nonlinear relationship between the input voltage and brightness, the signal must be correspondingly pre distorted. Gamma correction is always done at the source (camera).

A luminaire that uses burning gas as its light source.

An electronic device (analogue or digital) designed to mute low level signals so as to improve noise performance during pauses in the wanted material.

1. Generally, one versed in the field of electricity and its application. 2. A term used by professional stage lighting people to refer to those operating or utilizing luminaires and related equipment, such as stage cable, dimmers, etc.

A universally agreed subset of the MIDI standard, created to enable manufacturers to build synthesizers, synth modules and plug-in instruments that exhibit an agreed minimum degree of compatibility.

An electrical supply, usually portable, that comprises a diesel or gasoline powered machine and electromagnets for the purpose of generating electricity.

A pyrotechnic fountain that produces a controlled spray (plume) of sparks. Most produce either silver or gold sparks. Other variations include changing from gold to silver (transformation) or have a color flame in addition to the spark plume. Still others have a crackle or glittering effect. Typical devices range in size from approximately 1/2� to 2.5� (13mm to 64mm) diameter and 2� to 8� (50mm to 204mm) long. The gerb composition is usually contained between a clay plug at the bottom and a clay nozzle (choke) at the discharge end. For special applications, color-producing salts may be added to the mix to give a contrasting flame of 6� to 18� (152.4mm to 457.2mm) height at the nozzle. Gerb labels usually list the performance parameters with the duration in seconds listed first and height in feet or meters listed second.

A note played very quietly; the opposite of an accented note.

A term used to describe a filament, lamp or luminaire that is barely glowing.

Special wheel which rises rapidly in the air while emitting a spray of sparks and, sometimes, a whistle.

1. An unintended surge or brief interruption in an electrical current or signal. This can sometimes be detrimental to the integrity of the signal or to electronic equipment. 2. Any error in the execution of a cue from a control console.

Describes an unwanted short term corruption of a signal, or the unexplained, short term malfunction of a piece of equipment.

A button on a control console that executes a cue.

In the film and video industries, a general term for any opaque item placed into the beam of a luminaire that blocks a portion of the beam or the whole beam.

Warning to people on stage that the lights are about to be switched off. Normally said during lighting plotting sessions or technical rehearsals. Obviously should not be done if there is any risky work on stage, or if anyone is up a ladder / using power tools / working on platforms / rehearsing choreography etc.

An enclosed transportable costume rail with removable side which enables large shows to manage huge quantities of costumes

A large suspended cymbal that is struck with a large felt mallet. It has it's roots in the orient.

A small worklight, supplied with some control consoles and other equipment, that has a long, narrow, adjustable support, similar in appearance and mobility to the neck of a goose. They are usually removable and dimmable.

An ornamental note usually played just before a main note.

A slider on a control console that controls all other sliders on the console, including masters and sub masters.

An form of equaliser whereby multiple narrow segments of the audio spectrum are controlled by individual cut/boost faders. The name comes about because the fader positions provide a graphic representation of the EQ curve.

A software program designer�s way of creating an intuitive visual operating environment controlled by a mouse-driven pointer or similar

Variations in value from white, through shades of gray, to black on a display.

Room close to the stage for the performers to relax before taking the stage

1. The wood or metal framework located in the flies that supports the pulleys containing the steel wires or rope holding up scenery, battens, etc. 2. The metal structure of pipes in a studio ceiling for the purpose of hanging luminaires, power distribution equipment, or grip equipment. A ballast for carbon arc spotlight.

A term among other drum terms used to describe the way a beat feels when it not only has a steady tempo, but "feels" incredibly good within the music.

An individual's pay before taxes or other deductions

A conducting connection between an electrical circuit or electrical equipment and earth, or to some conducting item that serves in place of the earth. In most alternating current circuits, ground has a voltage potential of zero.

An alternative term for the electrical Earth or 0 Volts reference. In mains wiring, the ground cable is often physically connected to the planet�s earth via a long conductive metal spike.

A pyrotechnic device that functions on the ground (as opposed to an aerial shell that functions in the air) and that includes fountains, wheels, and set pieces.

A condition created when two or more devices are interconnected in such a way that a loop is created in the ground circuit. This can result in audible hums or buzzes in analogue equipment, or unreliability and audio glitches in digital equipment. Typically, a ground loop is created when two devices are connected together using one or more screened audio cables, and both units are also plugged into the mains supply with safety ground connections via the mains plug earth pins. The loop exists between one mains plug, to the first device, through the audio cable screen to the second device, back to the mains supply via the second mains plug, and round to the first device via the building�s power wiring. If the two mains socket ground terminals happen to be at slightly different voltages (which is not unusual), and small current will flow around the ground loop. Although not dangerous, this can result in audible hums or buzzes in poorly designed equipment.

The pin, prong, blade, or tab on some male connectors for the purpose of making a connection ground.

The truss, lifts, towers, etc. that are set up at ground, stage, or platform level and used to support other truss or equipment above.

To have a conducting connection to ground.

A collection of signals within a mixer that are combined and routed through a separate fader to provide overall control. In a multitrack mixer several groups are provided to feed the various recorder track inputs.

A stringed musical instrument with a fretted fingerboard, typically incurved sides, and six to twelve strings, played by plucking or strumming with the fingers or a plectrum

Member of the road crew who maintains and sets up the musical equipment for one or more guitarists

Set up and maintain all stringed instruments while a band is on tour

Material found in fireworks. This material can be used as a propellant charge, to produce sound, as a constituent of other compositions, or in the ignition fuse or timing system of fireworks. Also known as gun powder.

High Definition

High Definition Multimedia Interface. A digital interface used to transmit audio and video data in a single cable

The name for a family of gases used in lamps to maintain proper color temperature and to keep the inside wall of the envelope clean.

A note sounded literally by "hammering" down with a left hand finger, often performed in conjunction with a note first plucked by the right hand on the same string.

Drums played with the hands such as congas, bongos, djembes, etc.

A fuse or pyrotechnic ignition composition which continues to glow or burn slowly instead of burning at its normal speed. Such a fuse may suddenly resume burning at its normal rate after a long delay. If the hangfire goes completely out (is extinguished), it is termed a misfire.

Illumination that has a hard edge and produces sharply defined shadows. Often this light is very intense.

High frequency components of a complex waveform, where the harmonic frequency is an integer multiple of the fundamental.

The addition of harmonics that were not present in the original signal caused by non-linearities in an electronic circuit or audio transducer.

Chime-like sounds achieved in two ways: 1)�natural harmonics�- by touching a string at any equidistant division of the string length (typically 5th, 7th, and 12th fret), directly above the fret with left hand, and striking hard with the right-hand fingers or pick near the bridge where there is more string resistance; or 2)�artificial harmonics�- touching a string with the index finger of the right hand twelve frets higher than any fretted note and plucking the string with either the thumb or third finger of the right hand.

A triangular musical instrument consisting of a frame supporting a graduated series of parallel strings played by plucking with the fingers

Any debris produced or expelled by the functioning of a pyrotechnic device that is capable of causing personal injury or unpredicted property damage.

Used to produce an atmospheric haze, rather than clouds of smoke, an is used by many lighting designers to reveal airborne light beams

1. A general term for a fresnel spotlight. 2. The part of a follow spot that contains the light source, i.e., not the stand, ballast, or interconnect cable. 3. The part of a metal halide luminaire that contains the lamp, i.e., not the ballast or interconnect cable. 4. The part of an ellipsoidal spotlight that contains the reflector, i.e., not the lens barrel or the cap.

In the theater industry, the supervising electrician on a production, i.e.., the person ultimately responsible for all other electricians, luminaires, and related equipment, such as stage cable, dimmers, etc.

Performs the final and longest set of the night. Typically the act that is advertised for the show.

The available �safety margin� in audio equipment required to accommodate unexpected loud audio transient signals. It is defined as the region between the nominal operating level (0VU) and the clipping point. Typically, a high quality analogue audio mixer or processor will have a nominal operating level of +4dBu and a clipping point of +24dBu � providing 20dB of headroom. Analogue meters, by convention, don�t show the headroom margin at all; but in contrast, digital systems normally do � hence the need to try to restrict signal levels to average around -20dBFS when tracking and mixing with digital systems to maintain a sensible headroom margin. Fully post-produced signals no longer require headroom as the peak signal level is known and controlled. For this reason it has become normal to create CDs with zero headroom.

A headphone and microphone combination used in such communications systems with a beltpack

The "top" of the guitar, where the tuning pegs are.

A type of insurance coverage that pays for medical and surgical expenses incurred by the insured

A savings account used in conjunction with a high-deductible health insurance policy that allows users to save money tax-free against medical expenses

A filter which transmits visible light and either absorbs or reflects infrared in order to reduce the amount of heat in a beam.

A metal form whose sole purpose is to absorb heat on one surface and radiate that heat from other surfaces.

The standard measurement of frequency. 10Hz means ten complete cycles of a repeating waveform per second.

The two cymbals on a stand that open and close together. They are operated by the foot. Generally used on the left side of a drumset (right handed drummers).

The device that keeps the top hi hat cymbal attached to the rod.

Describes video having a dynamic range greater than that of standard dynamic range video

A filter which passes frequencies above its cut-off frequency, but attenuates lower frequencies.

A misnomer, but used to refer to digital formats with long word-lengths and high sample rates, eg. 24/96 or 24/192. Audio resolution is infinite and identical to analogue systems in properly configured digital systems. Word-length defines only the system�s signal-to-noise ratio (equivalent to tape width in analogue systems) , while sample rate defines only the audio bandwidth (equivalent to tape speed in analogue systems).

Devices propelled into the air, usually aerial shells

The upper portion of the audible frequency spectrum, typically denoting frequencies above about 1kHz.

Random noise caused by random electrical fluctuations.

Generic term for a lifting machine

A space designated in a person's residence for official business purposes. Can write off related expenses for tax purposes.

A clamp with a wing bolt for hanging a lantern on a horizontal lighting bar, so that it hangs below the bar

Imaginary lines drawn from the seats furthest from the center line of the audience area, to any obstructions on the sides of the stage, to determine what portions of the performing area will be visible to all of the audience.

To make a connection on a patch panel while the circuit is live, thereby creating a potentially dangerous arc.

The spot of light with the highest intensity, ideally located at or near the center of a beam that has been focused for a peak field.

1. The venue. 2. The audience

The electrician employed by a facility who is in control of house lighting and any electrical or electronic equipment owned or responsible for by the facility.

General lighting provided for the audience area.

The red, orange, yellow, green, blue, violet, magenta aspect of color, without regard to other aspects such as saturation and luminance, i.e.., the property of light that distinguished it from gray of the same luminance.

Corresponds to colors such as red, blue, etc. A color wheel contains basic pigments. All the hues of the rainbow encircle the cone�s perimeter. The wavelength of the color that allows color to be distinguished such as red, blue and green. Often used synonymously with the term tint. It is the dominant wavelength that distinguishes a color such as red, yellow, etc. Most commonly, video hue is influenced by a camera�s white balance or scene lighting. Video color processors, such as the video equalizer, are the main tools used to adjust and correct hue problems

Color space system based on the values of Hue, Saturation, and Intensity. Intensity, analogous to luma, is the vertical axis of the polar system. The hue is the angle and the saturation is the distance out from the axis.

Nearly identical to HSI except Intensity is called Lightness. Both serve the same function

Nearly identical to HSI and HSL except Intensity and Lightness are called Value. All three serve the same function

Audio Signal contamination caused by the addition of low frequencies, usually related to the mains power frequency.

An electric guitar pickup containing two magnetic coils rather than a single one, which gives a high output and minimizes hum from electrical interference

A system of controlling machinery or moving scenery using oil or water under pressure to move a piston or 'ram'. Used in many large-scale shows to automate scene changes.

The input/output connections of a system.

International Alliance of Theatrical Stage Employees; popular union for the concert production industry

Internal Revenue Service; in the US, responsible for the enforcement of income tax laws and collection of federal income taxes

Sensitivity to light

Gerb type device usually with no choke containing a pressed composition of nitrocellulose and titanium that produces a low smoke and lower height fountain effect than a conventional gerb. Typical heights are from 6� to 36� (15.3cm to 91.5cm) and durations of up to 45 seconds. Sizes range from �� to 1� (13mm to 25mm) in diameter and 4� to 6� (102 to 153mm) long.

To cause an arc to form across the electrodes of a light source, either manually, as with carbon arc sources, or by using an ignitor, as with arc lamps.

An Electro-Explosive Device (EED) that is used to remotely initiate other pyrotechnic devices by means of an electrical current.

Usually unlabelled, these devices exceed the federal maximum explosive charge allowed. Some examples are M-80s, M-100s, and silver salutes. These devices are extremely dangerous and should be avoided. Some members of the public and media incorrectly refer to these devices as fireworks.

1. Generally, a term for light or lighting. 2. In photometry, the amount of light, i.e.., luminous flux per unit area incident on a surface, in Footcandles or Lux.

A bit stream duplicate of the original data

The plane in which an image produced by an optical system is formed; if the object plane is perpendicular to the optical axis, the image plane will ordinarily also be perpendicular to the axis.

An electronic device that converts an optical image into an electronic signal

The �resistance� or opposition of a medium to a change of state, often encountered in the context of electrical connections (and the way signals of different frequencies are treated), or acoustic treatment (denoting the resistance it presents to air flow). Although measured in Ohms, the impedance of a �reactive� device such as a loudspeaker drive unit will usually vary with signal frequency and will be higher than the resistance when measured with a static DC voltage. Signal sources have an output impedance and destinations have an input impedance. In analogue audio systems the usually arrangement is to source from a very low impedance and feed a destination of a much higher (typically 10 times) impedance. This is called a �voltage matching� interface. In digital and video systems it is more normal to find �matched impedance� interfacing where the source, destination and cable all have the same impedance (eg. 75 Ohms in the case of S/PDIF).

The art of inventing music on the fly. This is achieved by knowing the structure of music, hearing it and inventing according to the rules

A wirelessly-connected foldback monitoring system, often used by musicians on stage with in-ear earpieces.

The emission of light from heated objects.

A term used to describe a lamp, or a luminaire that utilizes such a lamp, that employs the incandescence of a filament as its light source. Such a lamp was first developed by Thomas Edison (United States) and Joseph Swan (Great Britain), independently, in 1879.

Money received for work or through investments

1. An electrical power supply that is totally separate from the stage lighting control. Used for testing lanterns prior to connection to the lighting system and also for powering non-lighting equipment on stage and working lights. 2. A channel within the stage lighting control which has been temporarily switched to become independent from the rest of the channels which remain under the control of the operator.

Illumination that falls on an area or subject by reflection, e. g., bounce lighting.

Retirement plan for Americans that was designed specifically for contractors or employers with no full-time employees

An investing tool individuals use to grow funds for retirement savings; IRAs can consist of a range of financial products, such as cash, stocks, bonds, mutual funds, and more

A reactive component that presents an increasing impedance with frequency.�

A way of taking control of a rogue lantern (or lanterns) at the lighting desk during the operation of a show and removing them from any further lighting states, until the inhibit is removed. Can also be used for removing the front of house lighting from a curtain call state. See also SUBMASTER.

a recessed male connector.

The input impedance of an electrical network is the �load� into which a power source delivers energy. In modern audio systems the input impedance is normally about ten times higher than the source impedance � so a typical microphone preamp has an input impedance of between 1500 and 2500 Ohms, and a line input is usually between 10 and 50k Ohms.

The provision on a mixing console or �channel strip� processor of a facility to break into the signal path through the unit to insert an external processor. Budget devices generally use a single connection (usually a TRS socket) with unbalanced send and return signals on separate contacts, requiring a splitter or Y-cable to provide separate send (input to the external device) and return (output from external device) connections . High end units tend to provide separate balanced send and return connections.

Also known as Quickmatch. Black match that is encased in a loose-fitting paper or plastic sheath to make it burn extremely rapidly. Quickmatch is used for aerial shells and simultaneous ignition of a number of pyrotechnic devices such as lances in a ground display piece.

The nominal signal level generated by an electric instrument like a guitar, bass guitar or keyboard. Typically around -25dBu. Instrument signals must be amplified to raise them to line-level.

A material that does not conduct electricity.

An electronic component that includes circuits, rectifiers, and perhaps transistors and other electronic components, processed and contained entirely within a single, compact package with terminals for making electrical connections.

A luminaire that is robotic, i.e., certain functions such as panning, tilting, focusing, dimming, beam shaping and coloring, etc., are motorized and remotely operated from a control console.

An abridged version of Luminous Intensity.

An electric cable and connector assembly that electrically connects a ballast to a luminaire that uses an arc as its light source.

A device that acts as an intermediary to two or more other pieces of equipment. For example, a MIDI interface enables a computer to communicate with MIDI instruments and keyboards.

Disturbance to the normal or expected operation electronic devices, equipment and systems. The inhibition or prevention of clear reception of broadcast signals

A technique of combining two television fields in order to produce a full frame. The two fields are composed of only odd and only even lines, which are displayed one after the other but with the physical position of all the lines interleaving each other, hence interlace

A technology of CCD design, where rows of pixels are output from the camera. The sensor�s active pixel area and storage register are both contained within the active image area. This differs from frame transfer cameras that move all active pixels to a storage register outside of the active area.

Something that happens occasionally and unpredictably, typically a fault condition.

A form of non-linear distortion that introduces frequencies not present in and musically unrelated to the original signal. These are invariably based on the sum and difference products of the original frequencies.

The distance between two notes.

Accuracy of pitch in playing or singing, or on a stringed instrument such as the guitar

Structuring a chord with a note other than the root as the lowest note.

A list of goods sent or services provided, with a statement of the sum due for these; a bill

An adjustable aperture built into a camera lens to permit control of light transmission through the lens

An abridged, but commonly used version of Iris Diaphragm.

A separate room or enclosure designed to provide acoustic isolation from external noise.�

A device intended to prevent the transmission of physical vibrations over a specific frequency range, such as a rubber or foam block. The term can also be applied to audio isolation transformers, used to provide galvanic isolation between the source and destination, thus avoiding ground loops.

Under U.S. tax law, these are eligible expenses that individual taxpayers can claim on federal income tax returns which decrease their taxable income

Small, rapid variations in a waveform due to mechanical disturbances or to changes in the characteristic of components. Supply voltages, imperfect synchronizing signals, circuits, frequency pulses, etc.

A cut which two sequential shots of the same subject are taken from camera positions that vary only slightly if at all

An adaptor from one type of electrical connector to another

In the metric system, a graduated scale used to measure temperature with 0� (-273�C) being the total absence of heat (absolute zero). Each degree is the same magnitude as a degree in the centigrade scale.

�A very large drum made of copper or brass. Most often used in orchestras and symphonies. This drum has a foot pedal that is attached to the head mechanism. When the foot pedal is depressed, the kettle drum makes a unique, "boing" type of sound.

The principal source of light which establishes the character of the actor together with the atmosphere and mood of the scene.

An electronic musical instrument with keys arranged as on a piano

Another word for "bass drum". This is the largest drum on a typical drumset and it sits on the floor.

To disconnect electrical current to one, some, or all luminaires, motors, or other electrical equipment.

1000 watts.

Liquid Crystal Display.

Light Emitting Diode. A form of solid state lamp.

Short for electrics

All legal consumer explosives have mandatory labeling requirements. Included on these labels should be the manufacturer's name and address, cautions, and directions for use.

1. Any light source in a self contained package, comprising an envelope, filament or electrodes, base, contacts, gas, and any support structures. The source can be of the incandescent, fluorescent, or arc type. 2. Quite often this term is used interchangeably with Luminaire, especially in the theater industry.

To turn off the lamp (bulb) of a lighting fixture

To turn on the lamp (bulb) or a lighting fixture

Colloquial term for a tech only concerned with lighting

A thin cardboard tube packed with color-producing pyrotechnic composition used to construct ground display pieces.

A term that is often used interchangeably with Luminaire, and is preferred over Luminaire in Europe.

The amount of time between the instant a frame is captured and the instant that frame is displayed

The time delay experienced between a sound or control signal being generated and it being auditioned or taking effect, measured in seconds.

The direction and angle in which the strands are twisted in rope making

The part played by a guitar soloist in a rock band

The electric cable(s) or sleeved, insulated wires, attached to a luminaire or piece of power distribution equipment via a strain relief, that terminate in a connector for the purpose of providing an electrical connection to the electrical supply or to another luminaire.

A single thin, heat-resistant metal plate from an iris or some mechanical dimmers.

Each sling used as part of a multiple sling. A bridle leg is therfore one half of a two leg bridle

Italian for 'tied together'. If you hammer-on or pull-off notes, you're playing legato style.

Lekolite; an ellipsoidal reflector spotlight used in stage lighting

A commonly used term for an ellipsoidal spotlight. Named after its inventors Levy and Kook, the names Leko and Lekolite are trademarked by Strand Lighting Co.

A transparent material, usually glass, shaped to bend light rays as they pass through it. Colored lenses can also be used as color media.

The ability of a lens to transmit light, represented as the ratio of the focal length to the diameter of the lens. The largest lens opening (smallest f-number) at which the lens can be set. A fast lens transmits more light and has a larger opening than a slow lens

Drum lick or short drum fill. A lick can also be a quick "riff" or fancy beat.

A height adjustable stand or tower, sometimes motorized or operated with a crank mechanism or by gas or liquid pressure.

The composition that propels (lifts) the pyrotechnic device into the air.

Illumination, i.e.., the aspect of radiant energy of which a human observer is aware through the visual sense. Its electromagnetic shorter than infrared radiation, i.e.., approximately 380nm (violet) to 750 nm(red). A term that is often used interchangeably with Luminaire.

Electromagnetic radiation that has a wavelength in the range from about 400 to 750�nm and may be perceived by the normal unaided human eye

The way in which illumination of any color or quantity is spread over a particular background.

A flat panel display which uses an array of light-emitting diodes as pixels for a video display

A steel or iron, ladder-like apparatus used to hang a plurality of luminaires.

Unwanted light that escapes a luminaire from a location other than its intended opening.

Any apparatus used to measure various quantities of light, i.e.., color temperature, footcandles, lux, etc.

An instrument for measuring the intensity of light

Anything that emits light, such as an arc or a filament, or in early stage light, the flame of a burning wick or gas.

A general term used to describe any stray light, including light leak.

A stand with arms attached.

An electronic apparatus, run by an operator, that converts the settings of various items, such as sliders, switches, buttons, or some form of data input, into a digital or analog signal that is thereby transmitted to a control card, dimmer bank, or some other electronic apparatus. Some control consoles are also equipped with monitors.

Electronic device used in entertainment lighting design to control multiple lights at once; usually placed at the Front of House position

A group of individuals trained in lighting skills and techniques, and collectively assembled to work on a stage, film, or video production. The group may include any or all of the following stagehands: electrics, electricians, roadies, gaffers, grips, operators and lighting technicians.

The complete layout and presentation of the lighting designer.

One who plans lighting compositions, lays out light plots, directs the focusing of luminaires, and determines the various intensities, colors, looks, and cues for a lighting production.

One who is responsible for the execution of the lighting design for a production, and, in some instances, may also be the Lighting Designer.

The diagrammatic layout of luminaires and related equipment, and their application(s) for a lighting production.

One trained in the lighting skills and techniques necessary for the implementation of the lighting design for a particular production.

An obsolete source of intensely bright light, most recently used in followspots.Derived from a burning jet of oxygen and hydrogen impinging on a rotatable cylinder of lime.�

Part of a scenic automation or powered flying system - a switch positioned to send a signal to the controller when it's reached the end of it's travel.

The US-specific form or a private limited company; it is a business structure that can combine the passthrough taxation of a partnership or sole proprietorship with the limited liability of a corporation

An automatic gain-control device used to restrict the dynamic range of an audio signal. A Limiter is a form of compressor optimised to control brief, high level transients with a ratio greater than 10:1.

A rope length, once cut to length or installed for a specific function

A line rocket is a tube device designed to produce thrust. The device is attached to a carrier design to slide freely on a metal cable. Upon ignition, the line rocket quickly travels the length of the cable. The cable is strung taught from initiation point to termination point. The cable termination point often has a �catcher trap� to prevent the spent tube from traveling back up or down the cable. The device is initiated using an electric match and the electric match is attached in such a way as to fall free of the device upon ignition. Duration of the effect varies but is usually not longer than 5 seconds.

A nominal signal level which is around -10dBV for semi-pro equipment and +4dBu for professional equipment.

A device where the output is a direct multiple of the input with no unwanted distortions.

An electronic display that consists of segments of a liquid crystal whose reflectivity varies according to the voltage applied to them

Having any voltage potential in reference to neutral or ground.

1. The electrical power rating in Watts. 2. The equipment connected to a dimmer

An electrical load is a circuit that draws power from another circuit or power supply. The term also describes reading data into a computer system.

The process of moving the production into a venue prior to the show

The process of moving the production out of a venue after the show

1. The maximum electrical load that something, such as wire, fuses, electrical connectors, etc., can safely accommodate. 2. The maximum weight that something can safely accommodate.

An assistant(s) who loads or reloads aerial shells, comets, or mines into mortars

Stagehands who are based out of the local area, and help the touring crew to load in, operate, and load out the show successfully

A term used to describe a luminaire that has an effective intensity at a relatively long distance. This term is very subjective and dependent on the type of luminaire used.

A number of separate cables bound together for neatness and convenience.

repeating section of audio or video material, or of cartoon cells.

The process of defining a portion of audio within a DAW, and configuring the system to replay that portion repeatedly. Also, a circuit condition where the output is connected back to the input.

The perceived volume of an audio signal.

A device used to convert an electrical audio signal into an acoustic sound wave. An accurate loudspeaker intended for critical sound auditioning purposes.

An oscillator used as a modulation source, usually operating with frequencies below 20Hz. The most common LFO waveshape is the sine wave, though there is often a choice of sine, square, triangular and sawtooth waveforms.

Any of a class of fireworks devices that either perform below approximately 200 feet (60 m) or begin their display at ground level and rise to complete their effect. Some examples of low level fireworks are comets, mines, roman candles, and many consumer fireworks.

A filter which passes frequencies below its cut-off frequency, but attenuates higher frequencies.

Lower voltage lamps give more intense light than mains voltage lamps of the same wattage.

The lower portion of the audible frequency spectrum, typically denoting frequencies below about 1kHz

A graphic overlay placed in the lower area of the screen

The tension rods (or screws) that hold the hoop and drumhead onto the drum. Some refer to the lugs as the actual metal encasement that the tension rods screw into.

A unit of measurement for Luminous Flux.

A complete unit for the purpose of generating usable and somewhat controllable light that comprises one or more lamps, parts designed to distribute the light, parts used to position and protect the light source, and a means to connect the light source(s) to an electrical supply.

A measure of the light, i.e.., luminous flux, per unit area leaving a surface in a particular direction. This quantity was formerly known as Brightness.

A measure of the strength of a light source in a particular direction, in Candles or Candelas. It is independent of the distance from the source.

A metric unit of measurement for Illumination, i.e.., 1 lumen per square meter.

Multichannel Audio Digital Interface. Originally specified by the Audio engineering Society (AES) as AES10 in 1991. This unidirectional digital audio interface shares the same core 24-bit audio and status data format as AES3, but with different 'wrapping' to contain 56�or 64 synchronous channels at base sample rates, or 28 channels at�96kHz. It can be conveyed over unbalanced coaxial cables, or via optical fibres

A device that gives a visual readout of MIDI activity when connected between two pieces of MIDI equipment.

A term used to describe the physical interface by means of which the musician plays the MIDI synthesizer or other sound generator. Examples of controllers are keyboards, drum pads, wind synths and so on.

A standard file format for storing song data recorded on a MIDI sequencer in such a way as to allow it to be read by other makes or model of MIDI sequencer.

MIDI information can be interpreted by the receiving MIDI instrument in a number of ways, the most common being polyphonically on a single MIDI channel (Poly-Omni Off mode). Omni mode enables a MIDI Instrument to play all incoming data regardless of channel.

A sound generating device with no integral keyboard.

A device which splits the MIDI Out signal of a master instrument or sequencer to avoid daisy chaining. Powered circuitry is used to 'buffer' the outputs so as to prevent problems when many pieces of equipment are driven from a single MIDI output.

A format used for transmitting synchronisation instructions between electronic devices within the MIDI protocol.

the principal source of light which establishes the character of the actor together with the atmosphere and mood of the scene.

Primary set of speakers

The quality of a chord having its intervals as the 1st, 3rd and 5th notes of the major scale.

A term applied to a connector that contains the pins, prongs, blades, and/or tabs for insertion into the holes or slots of a female connector. The male connector should never be attached to the line side of a circuit.

A type of drumstick used to strike a percussion instrument; particularly a bell instrument such as the marimba or xylophone.

A technique used to ignite fireworks using a handheld ignition source such as a fusee or portfire.

A hollowed out gourd on a stick (rattle). Usually filled with seeds or pebbles. Another simply designed instrument but capable of many different types of sounds through various skillful techniques used by the drummer.

An instrument that consists of a large frame holding wooden resonator bars. This musical instrument is played with mallets.

Making marks on the floor with chalk or tape to indicate where parts of the show are going to be (i.e. motors, stage, scenic elements, speakers)

An electically detonated pyrotechnic device giving the effect of a loud explosion

1. A slider on a control console that controls groups of sliders on the console, including some or all sub masters, with the exception of the grand master, if the console is so equipped. 2. A term used to describe a control console that has control over another control console(s).

A device which controls slave devices. Often used to refer to synchronised recorders, or digital clocking devices.

The senior member of the theatre's stage lighting team, although not necessarily the lighting designer

In the theater industry, the supervising electrician on a production, i.e.., the person ultimately responsible for all other electricians, luminaires, and related equipment, such as stage cable, dimmers, etc.

A type of fast-burning fuse typically used to ignite multiple pyrotechnic devices. When ignited the match tape rapidly burns with little residue, transferring fire to the connected pyrotechnic devices. Match tape is typically comprised of a trail of fine-grained powder sandwiched between 2 strips of cellophane tape, which can be adhered to multiple devices and ignited with a single electric match.

Afternoon performance of a show

A patching apparatus that can be a patch panel or a diode pin matrix.

A combination or array of electromechanical or electronic switches which route a number of signal sources to one or more destinations.

The loudest sound pressure level that a device can generate or tolerate.

Abbreviation of megabits per second. One megabit is equal to one million bits or 1,000 kilobits. It is used to measure high data transfer speeds of connections such as Ethernet and cable modems.

A term used to describe a luminaire that has an effective intensity at a relatively moderate distance. This term is very subjective and dependent on the type of luminaire used.

A measure of computer memory or storage. It is one million bytes (in the context of computer memory, sometimes used to mean 1,048,576 (2 to the power 20) bytes).

Nominally 1,000,000 (one million) bytes of data, but in fact, because computer memory works in with binary, the actual value is 1,048,576 bytes (220).

The term pixel comes from the phrase picture element. One megapixel is equal to 1,000,000 (one million) pixels. For the most part, the larger number of pixels, the better the quality of the picture.

A control console that has computerized functions and an ability to electronically store data.

Goods to be bought and sold

A display intended to indicate the level of a sound signal. It could indicate peak levels (eg. PPMs or digital sample meters), average levels (VU or RMS meters), or perceived loudness (LUFS meters).

A clicking electronic device that sets tempo for a rhythm or song. It measures time in BPM (beats per minute). A popular "middle of the road" metronome setting is, quarter note = 120 bpm.

The nominal signal level generated by a microphone. Typically around -50dBu. Mic level signals must be amplified to raise them to line-level.

A device used to convert an acoustic sound wave into an electrical signal.

The middle portion of the audible frequency spectrum, typically denoting frequencies between about 300Hz and 3kHz.

A device containing multiple pellets (stars) of self-consuming pyrotechnic composition. The stars are propelled into the air via a lifting charge, producing various colors, glitter and crackle effects in an inverted cone pattern. Typically, proximate audience mines do not exceed 4 inches (102mm) in diameter and are selfcontained devices including the effect, lift charge, mortar and igniter.

Made from natural or synthetic minerals in the form of threads or fibres tangled together to form a moderately dense �blanket� which permits but impedes air flow and is useful in the creation of sound absorbers, often employed as a cheaper and more efficient alternative to polyurethane form.

The quality of a chord having its intervals as the 1st, flat 3rd and 5th of the major scale

A sphere whose surface is covered with a plurality of small, individual mirrors, that when rotated and shined upon by a light source, gives the effect of a multitude of moving spots of light swirling and sweeping across surrounding surfaces.

A device used to combine multiple audio signals together, usually under the control of an operator using faders to balance levels. Most mixers also incorporate facilities for equalisation, signal routing to multiple outputs, and monitoring facilities. Large mixers are also known as �desks� or �consoles�.

The characteristic distribution of resonant low frequency sound waves within a confined space such as a room.

Another word for scale. The major scale yields 7 modes, one starting and ending on each note.

An obsolete term for hardware digital recorders that can be used in multiples to provide a greater number of synchronized tracks than a single machine.

To change keys within a piece of music

A discrete apparatus that contains a dimmer card, its enclosure or mounting apparatus, and perhaps other related items such pilot lights or handles.

An apparatus that renders a visual representation of the instructional information that was, is, or will be sent from a control console to a control card, dimmer bank, or some other electronic apparatus, and also a visual representation of the status of these items.

A device that accepts video signals from a computer or video camera and displays information on a screen; a video display

The individual at a fireworks display responsible for observing the perimeter of the firing site and insuring that security personnel or barriers keep spectators at a safe distance. Usually provided by the organization sponsoring the event.

A device used to convert an electrical audio signal into an acoustic sound wave. An accurate loudspeaker intended for critical sound auditioning purposes. Also used to refer to a computer display screen (VDU), or the act of auditioning a mix or a specific audio signal.

A line-level audio signal control device used to select and condition input signals for auditioning on one or more sets of monitor loudspeakers. Some monitor controllers also incorporate facilities for studio talkback and artist cue mixes.

Responsible for the operation of the monitor mixing console, maintenance and repair of the band's inears, onstage, and backline gear. Maintains and repairs microphones, wedges, XLR cable, and any other audio gear

Responsible for the operation of the monitor mixing console, maintenance and repair of the band's inears, onstage, and backline gear. Maintains and repairs microphones, wedges, XLR cable, and any other audio gear

A single channel of audio.

Black and white with all shades of gray

One note at a time.

This device produces a bright flash, heavy smoke and often a rolling ball of fire. The device is sometimes designed to produce noise in conjunction with the visual effect. It is often pre -packaged in a canister or tube but can be assembled on site. Size varies depending on desired effect but typically ranges from �� to 5� (13mm to 127mm) in diameter. Larger variants of this device are often quite energetic and should be contained or mounted in an appropriate holder. Effect duration is intended to be very short, usually less that 1 second.

Above ground structure filled with sand or similar material into which mortars are positioned.

Sturdy wooden or metal frames used to support mortars in an upright position usually above ground.

The main circuit board within a computer into which all the other components plug or connect.

Pieces of digital footage or animation which create the illusion of motion or rotation

A group of standards for encoding and compressing audiovisual information such as movies, video, and music. MPEG compression is as high as 200:1 for low-motion video of VHS quality, and broadcast quality can be achieved at 6 Mbit/s. Audio is supported at rates from 32 kbit/s to 384 kbit/s for up to two stereo channels.

Generic term for an electric chain hoist

Mousing a shackle when rigging means using a wire or a cable tie to hold the shackle pin in place to stop it working loose

A dynamic microphone where the diaphragm supports a coil of wire which moves within a magnetic field. When sound causes the diaphragm to vibrate a small electrical current is generated within the coil. The same technology is used in reverse for a moving coil loudspeaker, in which a powerful current is passed through the coil, causing the diaphragm (cone) to move in response.

A luminaire that is robotic, i.e., certain functions such as panning, tilting, focusing, dimming, beam shaping and coloring, etc., are motorized and remotely operated from a control console.

A multiple shot device designed to produce a barrage of effects. The device specifications are similar to multi-shot devices, timed, except all devices fire simultaneously.

A multiple shot device designed to produce a succession of effects. Each tube is typically .6� to 1.38� (15mm to 35mm) in diameter. A single igniter initiates the first effect, with subsequent effects being ignited by the time fuse. The number of tubes, tube spacing and speed of the time fuse used determine the overall duration of the device. The type of effects typically used can be comets, mines, small aerial devices, crossette comets, audible effects or any combination of effects. Often multiple igniters may be used to alter the overall duration of the device.

A synthesizer, sampler or module that can play several parts or different sounds at the same time, each under the control of a different MIDI channel.

An electrical cable that generally has more than three conductors.

A connector that generally has more than three contacts.

Refers to a line-level signal splitting or distribution facility�typically found on�patchbays in which three or more sockets are wired together to allow an input signal to be shared with multiple destinations. As an entirely passive facility the operation relies on a very low source impedance and high destination (bridging) impedances to minimise the loss of signal level. Microphone 'mults' tend either to use transformers with multiple secondary windings or active buffer or distribution circuitry.

A recording device capable of recording several 'parallel' parts or tracks which may then be mixed or re-recorded independently.

A defined interface format that enables electronic musical instruments and computers to communicate instructional data and synchronise timing. MIDI sends musical information between compatible devices, including the pitch, volume and duration of individual notes, along with many other aspects of the instruments that lend themselves to electronic control. MIDI can also carry timing information in the form of MIDI Clock or MIDI Time Code for system synchronisation purposes.

To make silent

A technique used to muffle the ringing of notes, usually done with the edge of the hand placed gently on the strings near the bridge.

the physical angle between two microphones, used to specify various microphone array configurations (eg. 90 degrees for a Blumlein pair, or 110 degrees for an ORTF array).

Abbreviation for National Electrical Manufacturers' Association.

Code for Fireworks Display

Code for the Manufacture, Transportation, and Storage of Fireworks and Pyrotechnic Articles

Standard for the Use of Pyrotechnics Before a Proximate Audience

A non-profit group that promotes the safe enjoyment of consumer fireworks.

Organization which provides several standards that outline recommendations for the manufacture, storage, transportation, and execution of fireworks

The acoustic zone close to a sound source or microphone. Often used to describes a loudspeaker system designed to be used close to the listener � although some people prefer the term 'close field'. The advantage is that the listener hears more of the direct sound from the speakers and less of the reflected sound from the room.

A means of arranging two or more directional microphone capsules such that they receive sound waves from the directions or interest at slightly different times due to their physical spacing. Information about the directions of sound sources is captured in the form of both level differences between the capsule outputs, generated by aiming directional polar patterns in different directions, and the timing differences caused by their physical spacing. Specific forms of near-coincident microphones include the ORTF and NOS arrangements.

On a guitar, includes the frets, fretboard, tuners, headstock, and truss rod

Income after taxes and other deductions

1. The connection point in a data or wye system that is earth grounded, or electrically connected to an item that serves in place of the earth. 2. A term used to describe any point on a neutral conductor. 3. Without color.

A current carrying conductor that is electrically connected to neutral.

A filter that attenuates light evenly over the visible light spectrum. It reduces the light entering a lens, thus forcing the iris to open to its maximum.

The connection between structural members in a construction

Any unpleasant or unintended sound frequencies in the audio signal

The word noise originated in audio practice and refers to random spurts of electrical energy or interference. In some cases, it will produce a �salt-and-pepper� pattern over the televised picture. Heavy noise is sometimes referred to as snow.

A system using spectrally-shaped dither to improve the perceived signal-to-noise performance of a digital audio system.

The level of the noise present below the audio signal, measured in decibels (dB)

The process of removing noise from an audio signal

A system for reducing analogue tape noise or for reducing the level of hiss present in a recording.

1. A term used to describe a circuit that does not pass through a dimmer. 2. A term used to describe a circuit that does not pass through a dimmer.

A term which describes digital recording systems that allow any parts of the recording to be played back in any order with no gaps. Conventional tape is referred to as linear, because the material can only play back in the order in which it was recorded.

Anything involving communication without words

A socket is said to be normalised when it is wired such that the original signal path is maintained unless a plug is inserted into the socket. The most common examples of normalised connectors are the insert points on a mixing console.

Sharply attenuates frequency-specific noise like hums or electrical noises with minimal damage to the remaining audio; this is done by cutting a "notch" out of the frequency spectrum at that point

A device containing small amounts of pyrotechnic and/or explosive composition but does not fall under the category of consumer fireworks. Such devices produce limited visible or audible effects. Examples are snakes, tanks, poppers, and snappers.

The small grooved piece of bone that the strings sit in between the fretboard and the headstock.

A slotted plastic or bone component at the headstock end of a guitar neck used to guide the strings over the fingerboard, and to space the strings above the frets.

The rule which states that a digital sampling system must have a sample rate at least twice as high as that of the highest �audio frequency being sampled in order to avoid aliasing and thus reproduce the wanted audio perfectly. Because anti-aliasing filters aren't perfect, the sampling frequency has usually to be made slightly more than twice that of the maximum input frequency � which is why the standard audio rate of 44.1kHz was chosen�for a nominally 20kHz audio bandwidth.

Federal agency that inspects fireworks manufacturing plants. OSHA not only regulates non-fireworks specific aspects of plant safety (i.e. housekeeping, electrical requirements, employee training), but also the fireworks-related standards of NFPA Standard 1124.

When a frequency or pitch is transposed up by one octave, its frequency is doubled.

Referring to an odd or uneven time signature (not 4/4), such as 7/4 or 5/8

The beats that are not stressed. This word is also used to describe a musician that may play out of time.

A process carried out while a recording is not playing. For example, some computer-based processes have to be carried out off-line as the computer isn't fast enough to carry out the process in real time. Also used to refer to a remote-controlled machine which is not currently active.

Directional microphones are inherently more sensitive to sound from one direction, and the direction of greatest sensitivity is referred to as the principle axis. Sound sources placed on this axis are said to be �on-axis�, while sound sources elsewhere are said to be �off-axis�

Out of sight from the audience.

A unit of measurement for Resistance, Reactance, or Impedance.

The unit of electrical resistance.

A basic electrical formula that simply states that voltage is equal to electrical current multiplied by resistance, i.e.., V=IR.

A microphone or loudspeaker polar pattern with equal sensitivity in all directions (often abbreviated to Omni). Also the MIDI mode where data on all channels is recognised.

In sight of the audience.

A circuit that has a physical break or disconnection, whether intentional or accidental, in its electrical path.

A break in an electrical circuit that prevents current from flowing.

A term used to describe luminaires that use no lenses.

A manner of chord construction in which the member notes are broadly separated. See�closed voicing�above.

Lighting with no color filter.�

The first act that takes the stage. Typically plays for the shortest time.

A work light used by the operator of a control console.

The basic software that enables a computer to load and run other programs.

A person designated to operate a control console, follow spot, generator, or some other apparatus that requires some degree of training and/or skill to use.

The person with overall responsibility for the operation and safety of a fireworks display. The operator is also responsible for storing, setting up, and removing pyrotechnic materials or devices after a performance.

Allows you to zoom in or out on the subject in the viewfinder. This enables you to get a closer view of the subject before taking your picture

Splits a DMX universe so that it can have multiple outputs of DMX cable

�Bells consisting of tuned metal bars mounted on a rectangular frame and played with a mallet.

This refers to a signal's voltage above or below the median line. Inverting the polarity�of a signal swaps the positive voltage to negative voltage and vice versa. This condition is often referred to (incorrectly) as 'out-of-phase'.

A female connector.

The signal level at the output of an amplifier or other device.

The effective internal impedance (resistance which many change with signal frequency) of an electronic device. In modern audio equipment the output impedance is normally very low. Microphones are normally specified with an output impedance of 150 or 200 ohms, although some vintage designs might be as low as 30 Ohms.

The nominal output voltage generated by a microphone for a known reference acoustic sound pressure level. Output sensitivity is normally specified for a sound pressure level of one Pascal (94dB SPL), and may range from about 0.5mV/Pa for a ribbon microphone, to 1.5mV/Pa for a moving coil, and up to 20 or 30mV/Pa for a capacitor microphone.

Sturdy support legs that assist in stabilizing some stands and lifts. They are generally removable or easily folded away to assist in transporting or maneuvering the stand or lift.

The intentional use of overloaded analogue circuitry as a musical effect.

Recording new material to separate tracks while auditioning and playing in synchronism with previously recorded material.

To exceed the maximum acceptable signal amplitude of an electronic or electrical circuit. Overloading a device results in a noticeable increase in distortion but this may be deemed musically beneficial and desirable, or completely unacceptable and inappropriate, depending on context and intent. Overloading an analogue device typically results in the waveform peaks becoming flattened (so tending towards a square wave) and a consequent rapid increase in odd-order harmonic distortion where the distortion products appear at higher frequencies than the source signal fundamentals, but remain musically related to them. In�contrast, overloading a digital system inherently contravenes the Nyquest Theorum, since he generated harmonic distortion products generally extend far above half the sampling frequency, and so become aliased and actually appear at lower frequencies than the source fundamentals with a non-musical relationship. This is why digital overloads sound so obvous and unpleasant in comparison to analogue overloads.

A component of a complex sound which has a higher frequency than the fundamental frequency, but which is not necessarily related by a simple integer multiple (cf. harmonics)

A designation for a type of lamp. In the case, one with a parabolic aluminized reflector.

Point Of View

One unit of binary data capable of being routed through a computer network. To improve communication performance and reliability, each message sent between two network devices is often subdivided into packets by the underlying hardware and software.

When one or more packets of data travelling across a computer network fail to reach its destination

A resistive circuit for reducing signal level.

A technique used to muffle the ringing of notes, done with the edge of the palm.�

To move the signal to any point in the stereo soundstage by varying the relative levels fed to the left and right stereo outputs.

To rotate from side to side around a vertical axis.

A control found on mixers to move the signal to any point in the stereo soundstage by varying the relative levels fed to the left and right stereo outputs.

1. A general term that can refer to an overhead, butterfly, or large framed scrim, diffuser, or reflector. 2. An abridged version of Breaker Panel, Circuit Breaker Panel, Electrical Panel, or Panelboard.

An abridged version of Par Lamp, Par Can, or Par Light.

A generally lightweight luminaire that utilizes a PAR lamp. The beam characteristics depend on the type of PAR lamp used.

A generally lightweight luminaire that utilizes a PAR lamp. The beam characteristics depend on the type of PAR lamp used.

A reflector designed to align light rays generally parallel to the axis formed by the point source and the center of the reflector, eventually resulting in a cylindrical-to-wide beam. The reflector has the shape of a paraboloid.

A means of connecting two or more circuits together so that their inputs are connected together, and their outputs are all connected together.

A variable value that affects some aspect of a device's performance.

An equaliser with separate controls for frequency, bandwidth and cut/boost.

A circuit with no active elements.

To make electrical connections on a patch panel, i.e.., hard patching, or, to assign dimmers to channels on a control console, i.e.., soft patching.

An alternative term for a Program, referring to a single programmed sound within a synthesizer that can be called up using Program Change commands. MIDI effects units and samplers also have patches.

A system of panel-mounted connectors used to bring inputs and outputs to a central point from where they can be routed using plug-in patch cords. Also called a Jackfield.

A large, metal cabinet that comprises a plurality of female connectors electrically connected to dimmers, and a plurality of patch cords for the purpose of changing around the load(s) that are connected to the dimmer(s). Some patch panels use parallel bus bars electrically connected to dimmers, and another set of parallel bus bars mounted 90� to the first set and electrically connected to the loads, and slidable connectors that electrically connect any bus bar from one set to any bus bar from the other set.

A very thin, heat-resistant metal plate with a design cut out of its surface. When placed into the aperture of an ellipsoidal spotlight or follow spot via the pattern slot, an illuminated representation of the design is projected.

The maximum instantaneous level of a signal.

The amplitude (voltage) difference between the most positive and the most negative excursions (peaks) of an electrical signal. A full video signal measures one volt peak to peak.

A five-tone scale used often in rock.

An allowance or payment made for each day; used to cover expenses such as food, lodging, parking, etc.

An instrument that is struck with your hands or an object such as a drumstick or mallet. Examples include a drum, cymbal, tambourine, bell, triangle, etc.

A term popularized in drumming over the last 10 years. It refers to beat displacement where all beats will move forward say, one eighth note. This method will create numerous variations of rhythmic possibilities.

A means of powering capacitor and electret microphones, as well as some dynamic microphones with built-in active impedance converters. Phantom power (P48) provides 48V (DC) to the microphone as a common-mode signal (both signal wires carry 48V while the cable screen carries the return current). The audio signal from the microphone is carried as a differential signal and the mic preamp ignores common-mode signals so doesn�t see the common-mode power supply (hence the ghostly name, phantom). This system only works with a balanced three-pin mic cables. Two alternative phantom power specifications also exist, with P12 (12V) and P24 (24V) options, although they are relatively rare.

The relative position of a point within a cyclical signal, expressed in degrees where 360 degrees corresponds to one full cycle.

The fraction of a cycle through which a wave has passed at any instant, measured as an angle with 360� representing one complete cycle. "Phase" is often symbolized by �.

An effect which combines a signal with a phase-shifted version of itself to produce creative comb-filtering effects. Most phasers are controlled by means of an LFO

Also called RCA connector, it is a widely used cable connector for home audio and video equipment.

The science of measuring light and its properties.

A large keyboard musical instrument with a wooden case enclosing a soundboard and metal strings which are struck by hammers when the keys are depressed

A plectrum used for guitars to strum chords or individual notes

Plucking or producing a sound on the guitar in general, either with the fingers or a flatpick. Sometimes refers to playing a single-note melody line.

Small handheld motor controller that plugs into a cable connected to a winch or other motorized system

The part of a guitar that converts the string vibrations to electrical signals. Also the stylus/cartridge assembly used to replay vinyl records.

The electronic device used to pick up the sound of electric guitar strings. There are many types and configurations.

The relatively short electric cable, power cord, or leads on a luminaire or piece of power distribution equipment that may or may not have a connector installed.

A thin prong used as a contact on some male connectors and lamp bases.

A random signal with a power spectral density which is inversely proportional to the frequency. Each octave carries an equal amount of noise power. Pink noise sounds natural, and resembles the sound of a waterfall.

A spotlight that has an extremely narrow beam.

A long, hollow, cylindrical bar made from iron for strength, used for battens, booms, gridirons, etc.

A "C" shaped clamp with jaws that attaches onto a pipe and locks with the aid of a bolt, that when tightened, bites into the pipe and locks the clamp in place. It also has a secondary bolt for the attachment of luminaires, distribution equipment, etc.

The PIT, as it's called, is the non-marching section of the band where students play percussion instruments such as the marimba, the triangle, tambourine, sleigh bells, finger cymbals and timpani. There are also sometimes extra snare drums, bass drums and even drumsets in this area of the field.

The musical interpretation of an audio frequency.

Old fashion device used for tuning guitars. Works by tuning to the notes created by blowing into its six tubes.

A special control message specifically designed to produce a change in pitch in response to the movement of a pitch bend wheel or lever. Pitch bend data can be recorded and edited, just like any other MIDI controller data, even though it isn't part of the Controller message group.

A device for changing the pitch of an audio signal without changing its duration.

Short for Picture Element. The most basic unit of an image displayed on a computer or video display screen. Pixels are generally arranged in rows and columns; a given combination among the pixels of various brightness and color values forms an image.

Mathematical ratio that describes how the width of a pixel in a digital image compares to the height of that pixel

The ability to make each LED component within the fixture respond to a video signal

Warning symbol of a square-on-point configuration mounted on each side and each end of a truck, rail car, or freight container which informs the public and emergency personnel of the hazardous nature of cargo, as specified in 49 CFR, � 172.

A term used to describe a lens side that is perfectly flat.

A lens that is plano on one side and convex on the other. These lenses converge light rays passing through them.

The part of a computerised lighting control desk which enables the operator to recall cues from the electronic memory.

Official word for guitar pick.

List of preparations and actions required of technical crews during the performance (eg Sound Plot = list of sound cues and levels in running order.) In the US, the term plot refers to a plan. (eg Light Plot = scale plan showing lighting instruments).�

A male connector.

A self-contained software signal processor, such as an Equaliser or Compressor, which can be �inserted� into the notional signal path of a DAW. Plug-ins are available in a myriad of different forms and functions, and produced by the DAW manufacturers or third-party developers. Most plug-ins run natively on the computer�s processor, but some require bespoke DSP hardware. The VST format is the most common cross-platform plug-in format, although there are several others.

The rigging point or hanging point to which the lifting machine or suspension component is rigged. Can be temporary or permanent

The directional characteristic of a microphone

This refers to a signal's voltage above or below the median line. Inverting the polarity�of a signal swaps the positive voltage to negative voltage and vice versa. This condition is often referred to (incorrectly) as 'out-of-phase'.

Often placed in front of the camera lens in order to suppress glare

The most common MIDI mode that allows and instrument to respond to multiple simultaneous notes transmitted on a single MIDI channel.

The ability of an instrument to play two or more notes simultaneously. An instrument which can only play one note at a time is described as monophonic.

�A device placed between a sound source and a microphone to trap wind blasts � such as those created by a vocalist�s plosives (Bs, Ps and so on) � which would otherwise cause loud popping noises as the microphone diaphragm is over- driven. Most are constructed from multiple layers of a fine wire or nylon mesh, although more modern designs tend to use open-cell foam.

A connection for the input or output of data.

A gliding effect that allows a sound to change pitch at a gradual rate, rather than abruptly, when a new key is pressed or MIDI note sent.

A long tube containing slow-burning pyrotechnic composition that is sometimes used to ignite fireworks at outdoor fireworks displays.

A signal derived from the channel path of a mixer after the channel fader. A post-fade aux send level follows any channel fader changes. Normally used for feeding effects devices.

A general term that can mean heat, candlepower, and/or wattage.

A device which accepts a standard line-level input signal and amplifies it to a condition in which it can drive a loudspeaker drive unit. The strength of amplification is denoted in terms of Watts of power.

A chord consisting of the first (root), fifth and eighth degree (octave) of the scale. Power chords are typically used in playing rock music.

A term used to describe electrical equipment that is specially designed to intake electricity and route it to an output wiring device or devices. Wire, electric cable, and other electrical such as circuit breakers, terminal blocks, connectors, etc., are some of the items employed by power distribution equipment.

Anything that has the potential to provide voltage and electrical current, i.e., electrical power.

1. A sequence of performances of the same production. 2. A rehearsal of part or the whole show

An intermediate means of protection where an anchor is placed through which the climbing rope can run. In the event of a fall, the climber should only fall as far as the length of rope between them and the highest running belay will allow. The rope absorbs the energy in the fall

The blue working lights used backstage during a performance.

A plot sheet giving details of the changes between cues, as distinct from a state plot which gives the whole state of the system at any time. For example, a lighting plot on a manual board is normally a running plot. It is difficult to start a running plot half way through; often the operator has to go back to the beginning and work through until the required point is reached. However, it contains the minimum information necessary to perform the cues, and is therefore more efficient on a manual lighting desk or complex sound setup.

In the US, an S Corporation for tax purposes is a corporation that does not pay any income taxes and has limited personal liability

The acronym stands for 'Serial Advanced Technology Attachment' and is a computer interface employed for connecting standard ATA hard drives to a computer�motherboard. The SATA interface supersedes�the PATA (parallel ATA) interface which has been used since the 1980s. A variant of the SATA interface, called eSATA (with the 'e' standing for 'external'), permits the connection of external hard drives. it uses a slightly different connector but is otherwise a very similar interface.

Standard Definition

Serial Digital Interface. A standard for digital video transmission over 75 ohm coaxial cable using BNC connections

1. The Society of Motion Picture and Television Engineers. 2. The term is also used to refer to a form of time code developed for the film industry but now extensively used in music and recording. SMPTE is a real-time digital code describing hours, minutes, seconds and film or video frames. Usually conveyed as an audible warble.

The upright blade which sits in the bridge, often bone, where the strings sit.

A steel cable that has a clip on one end and a loop on the other. It is intended to be threaded through a piece of hanging equipment and around a support structure, such as a batten or truss, and then clipped to its loop. It then acts as a safety support should the primary support, such as a pipe clamp or hanging arm, fail.

A tube, closed at one end that is placed over the end of the fuse until intended ignition to protect it from damage and accidental ignition.

A safety sensor on the edge of a piece of automated scenery (usually a moving platform) that the automation system uses to detect something or someone out of place and take appropriate action.

1. A switch that disconnects electrical current to any uninsulated conductor that a person may come in contact with internally when a housing door is opened or damaged. The switch is automatically activated by the door or some part of the door, e. g., a lens. 2. A switch that disconnects electrical current to an apparatus if the apparatus or any part experiences an overtemp situation.

Fireworks designed to produce an explosive sound as its primary effect.

Either a defined short piece of audio which can be replayed under MIDI control; or a single discrete time element forming part of a digital audio signal.

The number of times an A/D converter samples the incoming waveform each second.

The aspect of color that determines the difference from white at a constant hue, i.e.., the property of any color that distinguishes it from a gray of the same brightness. High saturation is one with little or no white light added to the color, deep red e. g. Low saturation is one with a large amount of white light added to the color, light pink e. g.

In color, the degree to which a color is diluted with white light or is pure. The vividness of a color, described by such terms as bright, deep, pastel, or pale. Saturation is directly related to the amplitude of the chrominance signal.

So called because it resembles the teeth of a saw, this waveform contains both odd and even harmonics.

A device that produces a revolving shower of sparks spinning around a fixed axis. Device is usually mounted to a stand or holder with an axle or shaft with a keeper or pin to lock the device to the shaft. The device may spin in any plane from the vertical to horizontal. The device often consists of 2 �gerb� type devices joined end to end, typically with a spacer between the devices and a hole for the axle or shaft mounting. Alternate configurations include gerb devices set at angles to the rotation point and attached to a wheel causing the wheel to rotate. The wheel has a collar in the center to accommodate the axle or shaft for mounting. Gerbs may have colored flame tips that create a band of color within the spray of sparks. Duration of the effect is usually between 15 and 30 seconds.

A series of intervals, usually spanning an octave. Scales are more often viewed as a series of notes (generated by the intervals).

A set of predetermined light levels that can be set up on a control console in advance of need, and to which the operator may fade or go to when desired.

On tax form 1040, reports income or loss from a business operated as a sole propietor

Many types of projection screen are available. Some are multi-purpose, some only for front projection, some only for back projection. If a screen is not self-supporting, it often has eyelets around the outside edge which are used to 'lace' the screen onto a larger frame.

1. In the theater industry, a thin, gauze-like curtain. When illuminated from the front, it appears opaque, and when illumination is present behind it but not on it, the scrim becomes almost transparent. It can also appear translucent when there is some illumination directly on it, and some illumination present behind it, in the proper proportions. 2. In the film and video industries, a fabric panel, used for dimming, with the light source being a luminaire or sunlight. They are available in a variety of sizes and shapes, and materials of varying density. 3. In the film and video industries, a round, framed metal screen, available in various densities, placed on the front of a luminaire to act as a dimmer. They are also available such that only half of the frame is screened, therefore allowing for only a portion of the light beam to be dimmed.

An electronic, motorized apparatus that mounts on the front of a luminaire, and allows for the automatic placement of one of a number of gels to be placed in front of the beam.

Member of the wardrobe department who operates sewing machines and carries out other sewing tasks.

Tax that a small business owner or independent contractor must pay to the federal government to fund Medicare and Social Security

A device for recording and replaying MIDI data, usually in a multitrack format, allowing complex compositions to be built up a part at a time.

1. To prepare an aspect of the stage. 2. The complete stage setting for a show or part of a show

A ground display such as lancework, wheels, gerbs, fountains, and/or other devices, which function while on poles, frames, or other structures, attached to the ground.

A metal connecting device originally for joining chain, comprising of two parts. An open "bell" connects the items to be joined and a "pin" is fitted to make the link complete

Any percussion instrument that can be shaken. Usually a hollowed out container filled with beads or pebbles.

The cylindrical drum without hardware (lugs, rims, heads).

A mechanical isolator intended to prevent the transfer of vibrations which may be transmitted through a microphone stand from reaching a microphone where they would otherwise produce unwanted low frequency sound.

A type of igniter that is more energetic than a conventional electric match used to initiate shock tubing. Other types of shock tube initiators include shot-shell primers and plasma spark generators.

A hollow, flexible thermoplastic tube usually .12� (3mm) in outer diameter. When shock tube is initiated, light (flame), and a pressure wave travel along the length of the tube at very high speed. The pressure wave creates a loud noise at the terminal end of the tube. The use of shock tube in entertainment pyrotechnics is limited usually to the visual simulation of a lightning strike.

A term used to describe a luminaire that has an effective intensity at a relatively short distance. This term is very subjective and dependent on the type of luminaire used.

A very low resistance path that allows electrical current to flow. The term is usually used to describe a current path that exists through a fault condition.

A false floor built on top of the theatre stage, which contains technical elements such as automation tracks or revolves, concealed lighting or smoke effects. In some large shows, the show deck completely replaces the existing theatre stage, which is put back into position when the show has finished it's run.�

Ability to control the integration (of light) time to the sensor to less than 1/60 second; e.g., stop motion of moving traffic.

1. A rectangular, metal apparatus that resembles a Venetian blind in form and function, generally used as a mechanical dimmer or blackout mechanism on large spotlights. 2. Thin, movable, heat-resistant metal plates that are introduced into a beam such that a portion(s) of the beam is blocked off, i.e., framed, affecting the beam pattern, usually forming a sharp edge in the beam. They are used in various types of luminaires, but extensively in ellipsoidal spotlights, usually 4 (top, bottom, right, and left), and follow spots, usually 2 (top and bottom), always situated internally, and usually at the aperture. Framing shutters generally can be independently adjusted, but those used in follow spots usually move simultaneously with a single control mechanism.

A high-frequency whistling or lisping sound that affects vocal recordings, due either to poor mic technique or excessive HF equalisation.

A part of an audio circuit that splits off a proportion of the main signal to be processed in some way. Compressors use a side-chain process to derive a control signals to adjust the main path attenuation.

Imaginary lines drawn from the most extreme seats in the house to the performing area to determine what portions of the performing area will be visible to all of the audience.

An electrical representation of an audio event.

The route taken by a signal from the input of a system to the output.

The ratio between useful television signal and disturbing noise or snow.

The ratio of nominal or maximum signal level to the residual noise floor, expressed in decibels.

The waveform of a pure sinusoidal tone with no harmonics

A type of magnetic transducer or pickup for the electric guitar that electromagnetically converts the vibration of the strings to an electric signal

1. A term for an alternating current electrical supply that has one hot leg and a neutral leg, or, two different hot legs whose phases are 120� apart, with or without a neutral leg. 2. A term used to describe something that requires a single phase electrical supply to operate.

Sketch or map of the fireworks display site or of the area of a performance using pyrotechnic special effects.

The head of the drum. A drumhead is often referred to as a drum skin. This a thin piece of animal hide such as is sometimes still used on african drums, or a synthetic polymer head traditionally used on snare drums and drumsets.

A chord such as G/B, meaning a G chord with a B bass note

A device under the control of a master device. Often used to refer to synchronised recorders, or digital clocking devices.

A plastic or glass tube placed over the third or fourth finger of the left hand and used to play "slide" or glissando effects in rock and blues and other forms of traditional music.

A pre-packaged device that uses pyrotechnic material to create a plume of white or colored smoke. Duration and output will vary greatly depending on device used.

A compressed disc of pyrotechnic composition that produces a cloud of white or colored smoke upon ignition.

Electrically powered unit which produces clouds of white non-toxic fog by the vaporization of mineral oil

A term used to describe a cable used to carry multiple individual audio signals, typically between a stage and mixing console in live sound applications.

A lighting or sound cue with no fade time - the cue happens instantly.

One of the more common drums in marching bands and drumlines and the primary drum of a drumset. The "snares" are the wires on the bottom of the drum that give it that "buzz" sound. Standard size is usually 14" diameter by 5 1/2" in depth but can vary greatly. Snare drums are made from wood, metal or even forms of plastic. The drum heads are made from mylar and are often covered with a thin white coating. The drum heads on the bottom of a snare drum are often thinner to allow the snares to vibrate more.

A metal tube, available in various sizes and shapes, that mounts on the front of some luminaires to control light spill. Some snoots used in the film and video industries have a means to install circular rings, i.e.., apertures, to the front in order to change the size of the opening.

Heavy random noise

A common brand of electrical connectors in the entertainment industry, have 19-pins

Tax charged to both employers and employees to fund the Social Security program

1. A female connector. 2. A hollow, cylindrical shaped mounting item used to accept studs, generally equipped with a tee-handle or bolt for setting into the stud. This prevents the receiver-stud combination from unintentionally uncoupling, and can also prevent the stud from rotating within. 3. A relay holding device that comprises terminals for making electrical connections to the socket, and contacts that make the electrical connections to the relay. 4. A miniature hole with two internal contacts on a diode pin matrix for the insertion and electrical connection of diode pins. 5. In general, any threaded, round opening. 6. The part of a carbon arc luminaire that holds the carbon rods.

A beam pattern edge that is not very clear and distinguishable, i.e.., one with a fuzzy or blurry perimeter.

1. Illumination that produces shadows with a soft edge. 2. A luminaire that provides such illumination.

A term used to describe a patch system whereby the dimmers can be interchangeably assigned to any one of any number of channels. This type of patch system is usually found on memory boards.

The materials used to protect a sling or an object from sling damage

A person who is the exclusive owner of a business, entitled to keep all profits after tax has been paid but liable for all losses

1. A general term used to describe an electronic component that uses immobile solids, usually semiconductors, to do what moving parts, liquids or gases once did. Transistors, thyristors, and diodes are examples of solid state components. 2. A term used to describe an apparatus that uses these components.

A dedicated interface to transfer audio signals in and out of a computer. A Sound Card can be installed internally, or connected externally via USB2 or FireWire, and they are available in a wide range of formats, accommodating multiple analogue or digital audio signals (or both) in and out, as well as MIDI data in and out.

The Front of House Engineer checks every mic and line on stage for signal. The monitor engineer tweaks each performers' monitor mix so they can hear themselves on stage. Then the band performs a few songs while the front of house and monitor engineers dial in the mix.

The round hole on the front of most acoustic guitars

A measure of the intensity of an acoustic sound wave. Normally specified in terms of Pascals for an absolute value, or relative to the typical sensitivity of human hearing. One Pascal is 94dB SPL, or to relate it to atmospheric pressures, 0.00001 Bar or 0.000145psi!

Sets up and uses soundboard and other sound equipment during concerts or performances, ensuring that levels are correct and the sound mix is right

The use of materials and construction techniques with the aim of preventing unwanted sound from entering or leaving a room.

A means of arranging two or more microphone capsules such that they receive sound waves from different directions at different times � these timing differences being used to convey information about the relatice directions of those sound sources. The technique is usually used with omnidirectional microphones, although directional mics can also be employed. The best known form of spaced array is the Decca Tree. Mono-compatibility is often reduced because the timing differences between channels often results in comb-filtering colouration when the channels are summed to mono.

Pyrotechnic effect that creates a focussed burst of sparks from a small tube

An accurate loudspeaker intended for critical sound auditioning purposes.

A lantern within the lighting rig which is required for a specific moment or effect within the performance, and is not part of the general cover lighting.

An adaptor screwed onto the hanging bolt of an instrument to enable it to be used on an upright stand.

A metal plate placed around the lamp socket base of some luminaires to prevent light leak.

A quick sounding cymbal with short sustain. Small in diameter generally from 6" to 14". Most typically 6" to 10"

1. Generally, any connector that is electrically connected to two or more other connectors, all constructed as a single unit. 2. A twofer or threefer

The organization (person, group, or government agency) that arranges with a duly authorized fireworks supplier for its services in presenting a fireworks display or in providing fireworks for use in a display.

A profile spotlight

Generally, any of several types of luminaires capable of emitting a beam pattern that is round, or in some instances, oval in shape, but more specifically this term refers to fresnel spotlights, ellipsoidal spotlights, and follow spots.

A member of the fireworks display crew (either the operator or an assistant) who observes the firing and bursting of aerial shells and other display fireworks for the purpose of detecting proper mortar angling, noting the occurrence of duds, and observing for other potentially hazardous situations.

Thin steel plates with holes through which the arbor connecting rods pass.

A symmetrical rectangular waveform. Square waves contain a series of odd harmonics.

A raised floor or platform, typically in a theater, on which entertainers perform

A connection box terminating a multicore cable which is usually placed on a stage for the easy connection of individual microphone�cables.

The left side of the stage when facing the audience.

A luminaire intended to illuminate any portion of, or anything on, a stage or similar performing area, exclusive of practical lights and work lights.

A graphic representation that illustrates the performers' setup when they perform live; shows where performers and gear will be positioned

In the theatre industry, a piece of flush mounted power distribution equipment comprising a metal box with a hinged, protective cover, notches in the cover to allow for stage cable to enter the cover in the closed position, and one or more female connectors mounted internally for the purpose of supplying electricity to luminaires, or other electrical apparatuses. Its line side is hard wired.

The right side of the stage when facing the audience.

One trained in the physical skills and techniques necessary for the implementation of a stage production.

To be prepared to receive and hence execute a new cue, or to have just received a signal that a new cue is imminent.

A dollar amount that non-itemizers may subtract from their income before income tax is applied

The guitar is generally tuned EADGBE low to high.

Resonant low frequency sound waves bouncing between opposite surfaces such that each reflected wave aligns perfectly with previous waves to create static areas of maximum and minimum sound pressure within the room.

Fireworks materials that are compressed into small cubes or round pellets.

Mechanically isolates the operator's movement, allowing for a smooth shot, even when the camera moves over an irregular surface

Generic term used for a plain wire rope sling. Also used when referring to roof structural steel and individual steel beams or scaffold materials and so on.

Generic term used for a plain wire rope sling. Also, when referring to roof strucural steel and invidiual steel beams or scaffold materials and so on

Large oil drums that have had the tops cut off and hammered into a tuned percussion instrument. Common in the Caribbean Islands. Played with mallets.

When mixing complex audio material it is often useful to divide the tracks into related sections and mix those sections separately before combining the whole. In mixing film soundtracks, the material would often be grouped as a dialogue stem, a music stem, and an effects stem. Each stem might be mono, stereo or multichannel, as appropriate to the situation. In music mixing, stems might be used for the rhythm section, backline instruments, frontline instruments, backing vocals, lead vocals and effects � or any other combination that suited the particular project.

A lens consisting of tiered, concentric rings on one side that are segments of the flat portion of a plano-convex lens. The other side is convex. It controls the light similar in manner as a plano-convex lens.

By convention, two channels of related audio which can create the impression of separate sound source positions when auditioned on a pair of loudspeakers or headphones.

Twirling the drumsticks for showmanship on stage.

Drumsticks

Steel wire rope used to extend the length or reach of a hoist chain or to allow a hoist to reach the ground from the point

An item mounted to a piece of electrical equipment or a luminaire designed to retain a permanently installed power cord such that any reasonable pull or twist on the power cord will not cause the power cord to get damaged at the point of entry, fall out, or adversely affect the conductors within the electrical equipment, luminaire, or electrical connector.

A piece of leather or fabric worn to support a guitar when standing

A low-bit-rate encoding format intended for use over networks and the Internet. Streaming files match the encoded bit rate to the connection speed of the user, so the remote viewer can play audio or video with minimal stoppage without first downloading the entire video file.

1. To remove all lighting and related equipment for storage and/or transport when a production is over. 2. To cause an arc to form across the electrodes of a light source, either manually, as with carbon arc sources, or by using an ignitor, as with arc lamps.

A swivel device with a handle with a fixture that fits over the tuning keys.

The vibrating element that produces sound in string instruments such as the guitar, harp, piano, and members of the violin family

A multi-lamp luminaire with its lamps mounted in a straight row.

1. To cause an intense light source to turn on and off repeatedly at a relatively fast rate. This is usually done in an area devoid of all other illumination to create a flickering, slow motion effect. 2. An abridged version of Strobe Light. usually using an arc lamp as its light source.

Pre-packaged tube device that produces multiple flashes at the output end of the tube in various colors.

Performed with a pick or the fingers. Generally consists of brushing across 2-6 strings in a rhythmic up and down fashion appropriate to the tune being played.

A slider on a control console that controls groups of sliders on the console, and perhaps other sub masters. They can usually be controlled by masters and the grand master if the console is so equipped.

Frequencies below the range of typical monitor loudspeakers. Some define sub-bass as frequencies that can be felt rather than heard.

The removal of energy from various wavelengths of light, usually by filtering. When filters are superimposed, each tends to remove energy at the wavelengths it would have if acting independently.

A specific type of efficient loudspeaker system intended to reproduce only the lowest frequencies (typically below 120Hz).

Individual at a fireworks display who controls all product. This person ensures that shells are dispersed only as they are needed.

A term used to describe anything whose bottom surface, when installed, is flush with the surface to which it was installed. This term is used to describe certain types of connectors, lamp sockets, plug-in boxes, and gridiron junction boxes.

An instantaneous and usually brief increase in voltage or electrical current in a circuit. This can sometimes be detrimental to the integrity of a signal or to electronic equipment.

A chord consisting of the 1st, 4th and 5th notes of the major scale. The (4) in effect replaces the (3). This chord demands resolution.

Part of the ADSR envelope which determines the level to which the sound will settle if a key is held down. Once the key is released, the sound decays at a rate set by the Release parameter. Also refers to a guitar's ability to hold notes which decay very slowly.

Referring to the ringing of the drum or how long it resonates.

A sample of fabric to demonstrate the material to use on a costume, set design, or lighting gel

The optimum position for a microphone, or for a listener relative to monitor loudspeakers.

A semi-circular yoke with a slot running centrally though most of its length to allow for the mounting of luminaires at various angles.

To keep two sequences playing at the same rate (in sync). A slide show or a series of video clips can be synced to the beat on an audio track. A talking-head video needs to maintain lip-sync, so that the audio matches the mouth movements of the speaker.

When a beat or a musical phrase is syncopated.

The creation of artificial sound.

An electronic musical instrument designed to create a wide range of sounds, both imitative and abstract.

A part of the MIDI standard that allows manufacturers to define their own specific message formats, commonly used to dump and load a specific product�s patch data.

1. Jargon for any Rubber-sheathed power cable. 2. Tip Ring Sleeve. The three contacts on a stereo jack audio connector.

A type of quarter-inch jack plug with three contacts (Tip, Ring and Sleeve), used either for stereo unbalanced connections (such as on headphones) or mono balanced connections (such as for line-level signals). Physically compatible in size with the TS (Tip, Sleeve) quarter-inch jack plug used for electric guitars and other instruments.

A system of writing music for fretted instruments whereby a number or letter appears on lines representing the strings, indicating the fret to be played.

The metal device usually used on archtop guitars to anchor the strings beyond the bridge.

A cable or set of cables with a connector at only one end which is used for connecting a company's equipment directly to the mains supply in a venue. The connection should only be made by a qualified electrician with the power off!

A system designed to enable voice communication between rooms.

a thin disc with metal discs attached, the tambourine is a popular percussion instrument played with the hand against the palm used to enhance and color music

The part of a tape machine that transfers magnetic energy to the tape during recording, or reads it during playback.

A hammer-on technique that is done with the right hand.

Investment where taxes are paid at a future date instead of in the period which they incur

The amount of income used to calculate how much tax an individual or a company owes to the government for a given tax year; gross income or adjusted gross income

A contribution required by law to state and federal revenue levied by the government on worker's income, business profits, or added to the cost of goods, services, or other transatctions

A picture condition in which groups of horizontal lines are displaced in an irregular manner.

In the theater industry, a curtain hung at the top of a stage opening to make the opening of the proscenium arch adjustable. In the film and video industries, a set piece placed in front of a luminaire to hide it from view of the camera.

Usually the first time the show is rehearsed in a venue

Lens system designed to give a large image of a distant object

The rate of the 'beat' of a piece of music measured in beats per minute.

The speed of the rhythm or song.

The long screws (sometimes short) that attach the drum rim to the shell of the drum, with the drum head in the middle. You tighten the tension rods (or screws) to tune the drum.

A steady, fixed level tone recorded onto a multitrack recording, or passed over a signal connection to test the signal path and act as a reference when matching levels.

Pyrotechnic devices for professional use in the entertainment industry. Similar to consumer fireworks in chemical composition and construction but not intended for consumer use.

Protective metal or plastic loop used to reinforce and protect the eye at the end or a wire rope

1. A term for an alternating current electrical supply that has three hot legs, with each leg at a phase that is 120� apart from the other, with or without a neutral leg. 2. A term used to describe something that requires a three phase electrical supply to operate.

Uses two front lights separated by 60 degrees horizontally and one backlight to cover each lit area of the stage

A special power cord that has one male connector electrically connected to three female connectors via three separate cables or sets of sleeved wires.

How loud the signal has to be before compression is applied

The drum throne is the drummer's seat, also called a drum seat or drum stool. Typically the drum throne rests behind the hand drums or drumset but can be used for any instrument that requires sitting. Keyboard players often use a drum stool or throne.

To direct the light emanating from a luminaire in a particular direction.

The effective distance between a luminaire and the area or subject to be illuminated.

Figure used to calculate how large a projected image will be for a given distance to the screen.

A plastic pick which fits around the thumb and projects a blade out to act as a pick.

A bi-directional computer interface based on the PCI Express protocol, used for both data transfers and to connect display monitors (it supports DVI, HDMI, and VGA monitors via adapters). Introduced by Apple in 2011, Thunderbolt 1.0 supports bi-directional data transfers at 10Gbit/s, while Thunderbolt 2.0�(launched in 2013) operates at twice that speed. This means a Thunderbolt 2.0�interface (20Gbit/s) is five times faster than USB3.0 and 25 times faster than FireWire 800. The physical Thunderbolt port is the same as Apple's mini-DisplayPort connector, and can be used to integrate FireWire, USB and Ethernet connections via appropriate adapters or hubs. Thunderbolt 3.0 uses the USB-C connector to carry up to 40Gbit/s, and has a 100W power transfer capability with appropriate cables.

To connect the line side leads of power distribution equipment, dimmer racks, etc., to the primary electrical supply for a location, such as a company switch, circuit breaker panel, or other piece of power distribution. This is generally done with feeder cables.

To rotate up and down around a horizontal axis.

The tonal 'colour' of a sound.

he process by which images are recorded at less than the standard rate of frames per second thus extending the period of time that can be covered by the storage medium

A color low in saturation.

A single drum. Also, mounted tom tom drums on a drumset, most commonly played with drum fills. They are also called rack toms. Sizes for rack toms can range from 6 inches all the way up to 18 inches. The larger drums, instead of being mounted on top of another drum, will have metal legs attached to them and are called floor toms. Tom toms have two drum heads, a batter head on top and a resonant head on bottom. They have several tuning keys (lugs) and can be tuned with a drum key.

The tonic; the first note of a scale; the main note of a chord, the note the chord is named after. Also known as the "root".

A measure of the linearity of a device. The THD+N measurement includes the noise contribution as well and is an indication of the quality of an audio product.

Drive bands across the country while on tour

Manages financial aspects of touring, including budgeting, reconciling show settlements, and negotiating band, crew, and vendor deals

Manages transportation, scheduling, and the financial aspects of an artist's time on the road

Work to secure regional interviews, show previews, and concert reviews for every stop on an artist's tour

Drive show equipment across the country while on tour

The term dates back to multitrack tape where the tracks are physical stripes of recorded material, located side by side along the length of the tape.

The process of recording individual tracks to a multichannel recorder. Tracking is also often discussed in the context of MIDI guitar synthesizers or controllers where the MIDI output attempts to track the pitch of the guitar strings.

Individual retirement account established by the US; allowing individuals to direct pretax income toward investments that can grow tax-deferred

To convert from one compression format to another (that is, from DV video from a camcorder to MPEG-2 for DVD). Preferably done intelligently to minimize loss of quality from repeated compression, and not requiring fully decompressing the input and then recompressing to the output.

To write a solo, note for note, off of a recording.

�A device for converting one form of energy to another. Microphones and Loudspeakers are good examples of transducer converts between mechanical and electrical energy.

An electrical device in which two or more separate and electrically isolated coils of wire are wound around a common ferromagnetic core. Alternating Current passing through one coil creates a varying magnetic field which induces a corresponding current in the other coil(s). In�audio applications transformers are often used to convey a signal without a direct electrical connection, thus providing 'galvanic isolation' between the source and destination. Winding a transformer with different numbers of turns for each coil allows the output voltage to be increased or decreased in direct proportion � a feature widely employed in mains power-supply transformers to reduce the mains voltage to something more appropriate for the circuitry, for example, or in microphone preamp step-up transformers.�

An element of a sound where the spectral content changes abruptly. Most natural sounds start with a transient element before settling into something more steady-state, and it is often that transient element that provides most of the recognisable character of the sound source.

An effect applied to a change of shot to make it anything other than a simple cut.

The ability of light to penetrate through something.

The ability of a medium to allow for the transmission of light, expressed as a percentage.

A subjective term used to describe audio quality where the high frequency detail is clear and individual sounds are easy to identify and separate.

To change the key of a piece of music by a specific interval.

To shift a musical signal by a fixed number of semitones.

A form of modulation of the amplitude of a sound using an LFO.�

A technique performed with either a very rapid down-up movement of the pick or a pami plucking of the fingers.

The simplest, smallest chord there is, consisting of the 1st, 3rd and 5th notes of the scale.

Another one of the many percussion instruments used for special effects. It is a metal bar actually bent in the shape of a triangle and struck with a small metal mallet.

A symmetrical triangular shaped wave containing odd harmonics only, but with a lower harmonic content than the square wave.

Triaxal Cable similar to coaxial cable with the addition of an extra layer of insulation and a second conducting sheath. Provides greater bandwidth and rejection of interference than coax.

A rapid movement between two notes.

1. To finely adjust the height of battens, curtains, or any item whose exact height is critical. 2. To finely adjust the voltage output of some electronic dimmer at the lowest control setting. 3. To finely adjust the focus, beam direction, shutter positions, etc., for a group of luminaires set up for a production.

A group of three notes played where two would be played.

A form of digital audio meter which is capable of determining the absolute amplitude value of a digital signal by using oversampling to fully reconstruct the waveform.

A framework of alloy bars and triangular cross-bracing providing a rigid structure, particularly useful for hanging lights where no permanent facility is available

1. A structure fabricated from various truss sections, used to hold up luminaires, scenery, and/or other production equipment. Truss can be ground-supported, or suspended overhead with rigging. 2. A sturdy, lightweight support structure fabricated from tubular aluminum in various shapes and sizes.

A metal bar within a guitar neck which is tensioned so as to counteract the tendency for the neck to bend under the tension of the strings.

A steel rod which fits inside the neck of some guitars. Its tension can be adjusted to straighten the neck.

A short throw follow spot operated from a truss rig.

An electronic device used to tune guitars.

An electronic tuning device.

A standard tungsten filament lamp loses its brightness in its' lifetime. Tungsten Halogen lamps use a Quartz envelope ('bulb') filled with halogen gas to give an almost constant colour temperature. See Halogen Cycle.

The geared devices on the headstock used to tighten or loosen the strings. also known as Machine Heads.

The colloquial term to describe a loudspeaker drive unit optimised for the reproduction of high frequencies.

A commonly used type of locking blade connector that requires a twisting action to lock the mating connectors together, manufactured by Harvey Hubbel, Inc. The name "Twist-Lock" is trademarked.

A special power cord that has one male connector electrically connected to two female connectors via two separate cables or sets of sleeved wires.

Kettle drums are pitched instruments that are considered a part of the melodic percussion family. They are very large drums made of copper or brass, most often used in orchestras and symphonies. These drums have a foot pedal that is attached to the head mechanism. When the foot pedal is depressed, the kettle drums make a unique, "boing" type of sound. Also spelled "timpani".

Short wavelength source of light at the end of the visible light electromagnetic spectrum which causes specially treated materials to fluoresce on an otherwise blackened stage. Used for special effect and for lighting onstage technical areas (eg Fly Floors). Ultraviolet sources designed for stage use are known as Black Light sources (also known as UV-B) and have all harmful radiations filtered out.

A 2-wire electrical signal connection where the signal conductor is surrounded by a screen which provides a 0V reference and also guards against electrical interference.

A club, society, or association formed by people with a common interest or purpose; IATSE is the prominent union in the Concert Production Industry

To play the same melody using two or more different instruments or voices.

A condition where the output signal is the same amplitude as the input signal; the overall system gain is then x1 or unity.

Small cutter designed for unpicking a sewn seam

Light from below the actors - from a light source on the stage floor.

Part of the stage furthest from the audience

Video Graphics Array. 1. A graphics standard for video devices such as monitors and projectors. 2. The generic name of the 3-row, 15-pin connector with a plue plastic infill that is used to connect an external monitor to a PC

Video Jockey. An artist that mixes video into a live performance on the fly

An audio meter designed to interpret signal levels in roughly the same way as the human ear, which responds more closely to the average levels of sounds rather than to the peak levels.

A compression scheme in which each unit of input material can be compressed to different sizes. For MPEG-2 video, for example, this means that �easier� sequences (that is, with no motion) can compress to very small sizes, whereas �hard� sequences (with lots of motion and scene cuts) can compress to much larger sizes. VBR compression can take better advantage of the overall available bandwidth of a video transmission or DVD player by allocating the available bits intelligently to the difficult parts of a sequence.

A term used to describe an optical system whereby the lenses in a luminaire adjust such that a beam pattern with a hard edge can be attained at various sizes at various distances without sacrificing beam lumens.

The rate at which a key is depressed. This may be used to control loudness (to simulate the response of instruments such as pianos) or other parameters on later synthesizers.

The number of people who can be seated in a specific place, set by law

Similar to a xylophone but having metal bars and resonators that are driven by a motor. This motor helps to create vibrato sound. Played with mallets.

Pitch modulation using an LFO to modulate a VCO.

To vibrate by slightly altering a pitch higher and lower.

The electronic representation of a sequence of images, depicting either stationary or moving scenes. It may include audio.

A wideband amplifier used for passing picture signals.

The frequency band width utilized to transmit a composite video signal.

A device used to divide single video signals, while boosting their strength for delivery to multiple video devices.

Device used to select between different video sources and, in some cases, compositing video sources together to create special effects

What the camera operator looks through to compose, frame and focus the picture

An instrument of the violin family, larger than the violin and tuned a fifth lower

A stringed instrument of treble pitch, played with a horsehair bow

A signal processor that imposes a changing spectral filter on a sound based on the frequency characteristics of a second sound. By taking the spectral content of a human voice and imposing it on a musical instrument, talking instrument effects can be created.

The capacity of a synthesizer to play a single musical note. An instrument capable of playing 16 simultaneous notes is said to be a 16-voice instrument.

The arrangement of the member notes of a chord, or placement of the melody or bass line within a harmonic progression.

The pressure at which electric current is available. USA 120V, UK 230V

An amplifier in which the gain (or attenuation) is controlled by an external DC voltage. VCA's are used in a wide range of audio and musical equipment, such as fader-automation systems in large format mixing consoles, audio compressors, and synthesizers.

Often considered to be the force of electrons moving from one point to another. Technically not a force at all, but the potential for electrons to move from one point to another, as measured in volts

A form that an employer must send to an emplotee and the IRS at the end of the year; reports annual wages and the amount of taxes withhold from their paycheck

A guitar effects device where a bandpass filter is varied in frequency by means of a pedal control.

A stage pocket whose cover is flush mounted with the wall to which it is mounted.

The general name for the costume department, its staff, and the accomodation they occupy

Complete inventory of all the costumes in a production with a detailed breakdown into every separate item in each costume

Sound that has prominent bass frequencies, and higher frequency sounds are subdued

Generally, a color that is in the yellow-orange-red range.

A subjective term used to describe sound where the bass and low mid frequencies have depth and where the high frequencies are smooth sounding rather than being aggressive or fatiguing. Warm sounding tube equipment may also exhibit some of the aspects of compression.

An even, overall illumination over a large area.

A luminaire used to produce a wash.

A pyrotechnic fountain producing a falling plume of sparks usually arranged in a line to mimic a waterfall. Falls are typically hung from overhead rigging in an inverted (up side down) configuration. Paper tube construction, typically �� to 1� (19mm to 25mm) diameter, charged with a pyrotechnic composition producing silver or gold sparks.

A unit of measurement for heat or Electrical Power.

Unit of electrical power

A graphic representation of the way in which a sound wave or electrical wave varies with time.

The distance, measured in the direction of propagation, of a repetitive electromagnetic wave between two successive points.

A signal that has effects added

A lever attached to the bridge of electric guitars that can be used to alter the pitch of notes.

A single line over a single sheave used as a handling aid

The process of accurately callibrating the camera's color

A role is said to be 'white glove' if the person is not required or expected to help with setting up equipment, only in the operation of it.�

A random signal with a flat (constant) power spectrum density, ie. equal power within any frequency band of fixed width. White noise sounds very bright

Any lens with a short focal length and a wide field of view

The areas to the left and right of the stage or performing area not visible to the audience.

A wing-shaped nut that is used at the top of cymbal stands to secure the cymbals. It is also used for cymbal stands and to secure drums on their mounting hardware.

The out of view areas to the sides of the stage

A percussion instrument used to enhance and color music. Wood blocks are hollow in the center and create a full-bodied tone. There are many different shapes and sizes of wood blocks, each creating a specific pitch.

1. High wattage lights used in a venue when the stage / auditorium lighting is not on. Used for rehearsals, fit-up, strike and resetting. 2. Low wattage blue lights used to illuminate offstage obstacles and props tables etc. Known as 'Wing Workers', 'Blues' or 'Running Lights'.

To wrap a beam or truss with a sling. The short sling used for doing so.

A reduction of the recognized value of something; reduction of taxable income

A very robust and latching connector commonly used to carry balanced audio signals such as the outputs from microphones or line level devices. An XLR is a type of connector developed by US manufacturer, Cannon, and used widely in professional audio systems. The company�s original X-series connector was improved with the addition of a latch (Cannon XL) and a more flexible rubber compound surrounding the contacts to improve reliability (Cannon XLR). The connector format is now is available in numerous configurations, from many different manufacturers, and with several different pin configurations. Standard balanced audio interfaces � analogue and digital � use three-pin XLRs with the screen on pin 1, the �hot� signal on pin 2 and the �cold� signal on pin 3.

Multipin metallic connector. (3 pin for normal sound use, 5 pin for DMX, Colour Scrollers etc). Sometimes called Cannons after the original manufacturer.

A musical instrument consisting of metal or wooden bars that are tuned and played with mallets. Common in musical symphonies and orchestras.

A sturdy, U-shaped metal bracket that attaches to opposite sides of a luminaire, or, video and film industry reflectors, butterflies, etc., such that it allows either to tilt freely. A locking mechanism is provided to prevent slippage when the desired position has been achieved. Also provided at the center of the yoke is a hole, stud, or receiver for mounting the yoke.

The point at which a signal waveform crosses from being positive to negative or vice versa.

A term used to describe a luminaire with such a focus. Some ellipsoidal spotlights and many follow spots have a zoom focus system.

To enlarge or reduce, on a continuously variable basis, the size of a televised image primarily by varying lens focal length.

A term used to describe an optical system whereby the lenses in a luminaire adjust such that a beam pattern with a hard edge can be attained at various sizes at various distances without sacrificing beam lumens.

An optical system of continuously variable focal length, the focal plane remaining in a fixed position.

A means of measuring the slope or steepness of a filter. The gentlest audio filter is typically 6dB/Octave (also called a first-order slope). Higher values indicate sharper filter slopes. 24dB/octave (fourth order) is the steepest normally found in analogue audio applications.

Standard protocol used to efficiently transport DMX universes over the network