Additive Synthesis: The process of constructing a complex sound using a series of fundamental frequencies (pure tones or sine waves).

ADSR: Abbreviation for Attack, Decay, Sustain, and Release. These are the four parameters found on a basic synthesizer envelope generator.
When a key is pressed, the envelope generator will begin to rise to its full level at the rate set by the attack parameter, upon reaching peak level it will begin to fall at the rate set by the decay parameter to the level set by the sustain control. The envelope will remain at the sustain level as long as the key is held down. Whenever a key is released, it will return to zero at the rate set by the release parameter.

Aliasing: Aliasing is the term used to describe the unwanted frequencies which are produced when a sound is sampled at a rate which is less than twice the frequency of the highest frequency component in the sound.

Amplifier: A device with electron tubes or semiconducters that is used to increase the strength of a signal.

Amplitude: Amplitude is a term used to describe the amount of a signal. It can relate to volume in an audio signal or the amount of voltage in an electrical signal.

Amplitude Modulation: A change in the level of a signal. For example, if a Voltage Controlled Amplifier (VCA) were being modulated by a Low Frequency Oscillator (LFO), the result would be a periodic increase and decrease in the audio level of the signal. In musical terms this would be referred to as Tremolo. The abbreviation of Amplitude Modulation is AM.

Analog: Data (signal) presented in a non-digital, continuous form.

Analog Synthesizer: A synthesizer which uses voltage controlled analog modules to synthesize sound. The three main voltage controlled modules in an analog synthesizer are: Voltage Controlled Oscillator (VCO), Voltage Controlled Filter (VCF), and Voltage Controlled Amplifier (VCA).

Aperiodic Waveform: A waveform that does not have a repeating pattern.

ARP: American Recording & Performance Co, a company which introduced some amazung synthesizers in the late seventires and early eighties.

Arpeggiator: A device or computer program that sequentially moves a pattern of notes over a range of the keyboard.

Attack: The first parameter of an envelope generator which determines the rate or time it will take for the event to reach the highest level before starting to decay.

Attenuator: Attenuate means to reduce in force, value or amount. An Attenuator is a device that reduces the value of something, usually the amplitude of a signal.

Audible Range: The range of frequencies that the human ear can hear. A healthy young human can usually hear from 20 cycles per second to around 20,000 cycles per second (20-20,000 Hz).

Auto Correlation: A process that determines optimum start and ending loop points to produce minimum discontinuity.

Auxilary Controllers: These are external controlling devices used in conjunction with a main instrument or controller. Some examples of such controllers are foot pedals, pitch bending and modulation wheels.

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Band Pass Filter: A filter which allows only a selected band of frequencies to pass through while rejecting all other frequencies above and below the cutoff point.

Baud Rate: The speed at which digital information is passed through a serial interface expressed in bits-per-second. MIDI data is transmitted at 31.25 KBaud or 31,250 bits per second.

Binary: Of or based on the number two or the binary numeration system (base 2). Digital computers use this form of numbering because the values of 0 and 1 can easily be represented by an open or closed switch.

Bit: A Bit is a single piece of information assigned a value of 0 or 1 as used in a digital computer. Computers use digital words which are combinations of bits. A Byte is a digital word consisting of eight Bits.

Boot: Starting up a computer by loading a program that allows it to run other programs. The term comes from bootstrapping which means that the computer "pulls itself up by its own bootstraps."

Bounce: When recording or sequencing, to bounce tracks means to combine (mix) several tracks together and record them on another track.

Buffer: An area of computer memory that is used to temporarily store data.

Bug: An error in a computer program that causes it to work incorrectly.

Byte: A computer word made up of eight bits of data.

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Cardioid: (kar' de-oid') A directional microphone with a heart shaped, narrow pattern, which picks up from directly in front of the mic.

Catalog: A list of all files stored on a disk or in a bank. Sometimes called a directory.

Cent: Unit of pitch equal to 1/100 of a semitone.

Center Detent: A notch in the center of a modulation wheel or lever which allows the performer to find the home position.

Central processing unit (CPU): A microprocessor or computer which is used to perform complex task-related functions. Within an electronic musical instrument, it is a dedicated computer system for handling the many performance and control-related messages and commands that must be processed in real time.

Channel messages: These are messages that are assigned to a specific MIDI channel within a system or device.

Channel-voice messages: These are used to transmit real-time performance data throughout a connected MIDI system. They are generated whenever the controller of a MIDI instrument is played, selected, or varied by the performer.

Channel, Output: The circuitry through which an instrument outputs individual notes.

Channel, MIDI: An information pathway through which MIDI information is sent. MIDI provides for 16 available channels, each of which can address one MIDI instrument.

Channel, MIDI Control: A MIDI Channel also contains information about which controllers are being varied.

Chip: An integrated circuit.

Chorus: A voice doubling effect created by layering two identical sounds with a slight delay (20-50 mS) and slightly modulating the frequency of one or both of the sounds .

Click sync/click track: this refers to the metronomic audio clicks that are generated by electronic devices to communicate tempo.

Clock: A steady pulse from a generator which is used for synchronizing sequencers, drum machines, etc. Common sequencer timing clock rates are 24, 48, or 96 pulses-per-quarter note. MIDI timing clocks run at a rate of 24 ppqn.

Clipboard: A temporary holding place in RAM for what you last cut or copied.

Close Miking: A microphone placement technique which involves placing a microphone close to the sound source in order to pick up mainly direct sound, and avoid picking up reverberant sound.

Computer Interface Hardware which enables a computer to communicate with other devices. A common example is a MIDI interface, which allows a computer to communicate with a musical instrument.

Condenser Mike: A microphone which converts sound pressure level variations into variations in capacitance and then into electrical voltage.

Continuous Controller: Refers to Midi information other than notes. For example, volume, pitch bending, modulation (vibrato). These parameters can change continuously over time and allow electronically generated music to sound more expressive.

Contour See Envelope Generator

Controller: A device which let's you enter or change events into a computer or other digital device. Examples include keyboards, pitch and modulation wheels and wind controllers.

Copy: To make a copy of something, either a sound or segment, by selecting it and choosing the copy function from the module menu. What is copied is placed on the clipboard.

Crossfade: To gradually fade out one sound while fading in another so that a seamless transition is made between the two sounds.

Cursor: A visual indicator showing the position of the next entry.

Cut: To remove something, either a sound or a segment, by selecting it and choosing the cut function from the module menu. What you cut is placed on the clipboard.

Cutoff Frequency: The frequency above which a low pass filter will start attenuating signals present at its input. Abbreviated Fc.

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DAT (machine): See Digital Audio Tape recorder.

Data: Information a computer needs in order to make decisions or carry out a particular action.

Data Wheel: A knob that allows you to scroll through Programs and change parameter values. Usually used when a keypad is not available or for fine tuning and scrolling through infinite variables.

dB/Octave: The unit typically used to indicate the slope of a filter, or how fast the frequency response rolls off past the cutoff frequency. Example: A 24 dB/octave filter would attenuate an input signal by 24 dB one octave above the cutoff frequency, by 48 dB two octaves above the cutoff frequency, and so on.

Decay: The second stage in an ADSR type envelope generator. See ADSR.

Decibel (dB): A reference for the measurement of sound energy. The minimum change in volume that the human ear can perceive. Named after Alexander Graham Bell. A decibel is 1/10th of a Bel.

Delay: A controllable time parameter giving the ability to start an event only after a predetermined amount of time.The Delay function on the EIII allows you to delay the start of a sound from 0 to 1.5 seconds from the time a key is pressed.

Depth: The amount of modulation. Sometimes called Amount, Width, Intensity or Modulation Index.

Digital: Equipment that uses quantities represented as binary numbers. In a digital synthesizer every aspect of the sound generation is handled as a numeric calculation. The digital information is not audible and so must be converted to analog form by a DAC before it is output.

Digital to Analog Converter (DAC): A device which interprets Digital information and converts it to Analog form. All digital musical instruments must have a DAC so that we can hear their output.

Digital Audio Tape (DAT): The medium that a machine that records sound digitally uses. They generally use a spinning drum similar to those found in VCR's as opposed to the record and playback heads found on regular analog tape recorders.

DSP: See Digital Signal Processors.

Digital Signal Processor: Most signal processors these days are digital. They allow the instant recall of all the parameter settings of the device without having to manually reset all the controls every time a different sound effect is required. Increasingly DSP's are becoming software based, accessed via an audio recording or editing application as a plug-in.

Direct time lock (DTL) and enhanced time lock (DTLe): A synchronization standard that allows Mark of the Unicorn's Mac-based sequencer, Performer, to lock to SMPTE through a converter which supports these standards

Display: A device that gives information in a visual form.

Distant Miking: A microphone placement technique which involves placing a microphone far from the sound source in order to pick up a high proportion of reverberant sound.

Drum Machine: A sample based digital audio device that makes use of the playback capabilities of ROM (read only) memory to reproduce carefully recorded and edited samples of individual instruments which make up the modern drum and percussion set.

Drum Pads: The playing surface buttons which are designed into a drum machine and played with the fingers.

Drum-pad controller: Such a controller offers the performer a larger, more expressive playing surface that can be struck either with the fingers and hands, or with mallets and drum sticks for full expressiveness. Additionally, a drum controller will often offer extensive setup parameters.

Dynamic Allocation: On the EIII, Dynamic Allocation defeats any pre- assigned output channel assignments and assigns the output channels according to a modified circular algorithm.

Dynamic Mike: A microphone in which the diaphragm moves a coil suspended in a magnetic field in order to generate an output voltage proportional to the sound pressure level.

Dynamic Range: The range of the softest to the loudest sound that can be produced by an instrument. Or the range of the low and high signal levels obtainable by a velocity sensitive keyboard. The greater the Dynamic Range, the more sensitive the keyboard.

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Edit: To change or modify information. To change parameters or alter existing data.

Envelope Generator: A circuit, usually triggered by pressing a key on a keyboard, that generates a changing voltage with respect to time. This voltage typically controls a VCF or VCA. An AHDSR and ADSR are two types of Envelope Generators. See ADSR.

Equal Temperament: A Scaling system where the octave is divided into 12 equal parts. The ratio of the frequencies between any two adjacent notes is exactly the same. Most keyboard instruments are scaled in this manner.

Equalizer: A device which allows attenuation or emphasis of selected frequencies in the audio spectrum. Equalizers usually contain many bands to allow the user a fine degree of frequency control over the sound.

Error Message: A message shown in the display to alert the user that an error of some type has occurred.

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Fast Fourier Transform: A computer algorithm which derives the fourier spectrum from a sound file.

Fc: See Cutoff Frequency

Filter: A device used to remove unwanted frequencies from an audio signal thus altering its harmonic structure. Low Pass filters are the most common type of filter found on music synthesizers. They only allow frequencies below the cutoff frequency to pass (Low Pass). High Pass filters only allow the high frequencies to pass, and Band Pass filters only allow frequencies in a selected band to pass through. A Notch filter rejects frequencies that fall within its notch.

FireWire: FireWire is a cross-platform implementation of the high-speed serial data bus -- defined by IEEE Standard 1394-1995 -- that can move large amounts of data between computers and peripheral devices. It features simplified cabling, hot swapping, and transfer speeds of up to 400 megabits per second. For more information go here.

Flange: An effect created by layering two identical sounds with a slight delay (1- 20 mS) and slightly modulating the delay of one or both of the sounds. The term comes from the early days of tape recording when delay effects were created by grabbing the flanges of the tape reels to change the tape speed.

Floppy Disk: A thin portable disk used to store digital data.

Fourier Spectrum: The description of a sound that is in terms of its distribution of energy versus frequency rather than its amplitude versus time (waveform).

Frequency: The number of cycles of a waveform occurring in a second.

Frequency Modulation: The encoding of a carrier wave by variation of its frequency in accordance with an input signal.

FSK: Frequency Shift Keying. An audio tone (frequency) modulated by a square wave, which is used both for data transfer and also for sequencer and drum machine synchronization.

Fundamental: The first, lowest note of a harmonic series. The Fundamental frequency determines a sound's overall pitch.

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Gain: The factor by which a device increases the amplitude of a signal. Negative gain will result in the attenuation of a signal.

Glissando: A rapid slide through a series of consecutive tones in a scale like passage. On an E-mu Sytems Emulator III arpeggiator for example, when two notes are played with glissando on, every note in between the two notes will be played in a sequential order. Similar to portamento except that the pitch changes in semitone steps.

Ground Loop: Hum caused by currents circulating through the ground side of a piece of equipment or system. This is due to grounding it at points of different voltage potential.

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