ANALOGUE - An analogue device is one which uses no encoding of information, and sets up a reasonably accurate analogy between the source signal (circuits) and the end phenomenon (speakers).


  CONTROL VOLTAGE - In the CV/Gate electronic musical instrument control system, a voltage set within a specified range which can determine the pitch of the playback of the instrument which is being Triggered.


  CV/GATE - An old system for controlling one electronic musical instrument with another. 'CV' stands for Control Voltage, (see above) and "Gate" refers to the on/off signal, which is called the 'Trigger'. Basically, we used to have to connect 2 or 4 cables between devices:
CV in
CV out
Gate in
Gate out
   The problem with this system was that no two manufacturers used the same voltages, so instruments of different manufacturers could communicate either poorly or not at all. MIDI fixed all this.


  DIGITAL - A digital device is one which stores and uses information necessary to its functioning in an encoded, digital format, and usually contains one or more microprocessors. (mini-computers)


  DIGITAL SAMPLER- The big music revolution.
In the 70's, Bell labs finally worked out a replacement system for the miles of tapes that the phone company was using to play the "The number you have reached..." messages. Now they could just store those recordings digitally in memory chips and magnetic discs, using computers to play them back, instead of clumsy tape recorders.
The way it works is this: A device called an analogue to digital converter (A to D) listens to a sound signal coming into it. Thousands of times a second, (44,100 times a second for music, nowadays) it "samples" the voltage. It then records the exact voltage level from that moment, and does it again. Meanwhile, the voltage has changed slightly, because the sound source is continuing to modulate the voltage. By the time the sound has been completely "sampled" in this way, the computer has stored many thousands of bytes of data which comprise a digital recording of the sound source.
   To play the sound back, a digital to analogue converter (D to A) does the same process in reverse: It takes the first number in the data file which was created during the recording process and sets the voltage of the output circuit to that level. Then it does the second one, and so on, throughout the data file.
People soon saw that this could be used to play back short recordings of single notes or musical instruments, and that they could be played back from a piano-style keyboard, like those used on synthesizers. The E-Mu company in Santa Cruz, CA were the first to successfully market such a device in, I believe, 1980, called the "Emulator". Now you could play a trumpet from a keyboard, but better yet, after MIDI came along, you could write the trumpet part in your sequencing software, and have the computer play it back for you. Then Art Of Noise realised that you could have it play back ANY sound, and the 80's were born.
   A digital drum machine is essentially a small
digital playback device with a set of percussion sounds, plus a small, hard-to-use sequencer.


  EQUALIZATION- Changing the relative volumes of different parts of the frequency spectrum in a sound or set of sounds. What this usually means for the average home stereo is boosting the highs, or the bass. In a live concert setting, the name "equalization" is appropriate, because the process usually starts with identifying certain regions of the frequency spectrum which are being accentuated or reduced by the geometry and materials of the room in which the sound system is operating. Equalization is then used to increase frequencies which are being reduced by the room, or to decrease frequencies being increased by the room. Eventually, (with luck) all the frequencies are equalized.


  Flanging - Regular changes in the relative volumes of different harmonics in a sound. This effect is usually created by playing two copies of a sound at nearly the same pitch, but with the pitch of one or both copies slowly changing very slightly, so that different frequencies are accentuated or cancelled out over time. The reason it is called "flanging" is that the original method for doing this (1960's or even earlier) was to have two copies of the recording on reel-to-reel tape both playing into the same mixer. Since the tape machines were playing at slightly different speeds, a dynamic change in the frequencies accentuated would occur. This process could be partially controlled by holding your finger on the edge of the tape reel to slow it down. The edge of the tape reel is also called a "flange".


  FM - Frequency modulation. An FM synthesizer differs from and analogue synthesizer in that its oscillators form their signal by combining several sine waves together. The user can control the pitch and amplitude envelope of the sine waves, as well as the relationships between them, to create sounds unattainable through normal synthesis. This was really big in the mid 80's, but then people got really sick of it.


  MIDI - Musical Instrument Digital Interface. A defined protocol for comminication and control between different electronic musical instrumets, or computers, or stage lights, or video equipment, etc. For more information on MIDI, follow this link.


  MIXER- A device which receives more than one audio signal and mixes them together into one. The point of a mixer is usually that one can adjust the relative volumes of the sounds being fed into the mixer. That big huge table-shaped thing with a million buttons that the sound guy is messing with in concerts is the mixer.


  MONOPHONIC - Able to play only one note or sound at one time. If the device has more than one Oscillator per Voice however, and those Oscillators are tunable, it is possible to get more than one note out of this one voice.


  OSCILLATOR - A part of a sound device which generates the electrical signal sent to the outputs to be heard as sound.


  PERCUSSION PADS - A percussion pad is any device which provides a surface to strike with a drumstick or other object (or your hand) which sends an electrical signal out of a cable when you do so. Most commonly, a small microphone is attached to the underside of the pad and converts the soundwave of the impact of the stick on the pad to an electrical signal. Most modern pads can send out a signal of varying strength, from which can be derived approximately how hard the pad was struck.
   Typically, the electrical signal is received by a small computer-controlled device with sends out
MIDI data to correspond with the electrical signal's arrival time. These MIDI note numbers are sent to MIDI-equipped electronic musical instruments, such as digital samplers. The instrument then plays the note which corresponds to the number sent out by the percussion pad's host computer, completing the connection between drumstick and musical note. (Or screaming explosion sound effect)


  POLYPHONIC - Able to play more than one note or sound at one time.


  RECORD POOL - A service provided to club DJ's for a fee. The record pool obtains free copies of singles from record labels, and then sends them out on a regular basis to member DJ's. The point of this is that it keeps the DJ's current with new material as it comes out, with no effort on the part of the DJ's.


  SEQUENCER - A device for storing and playing back information about how to play musical instruments.
Technically, writing notes on paper counts as a crude sequencer. Some dacedes ago, devices were made which could be set to send out a
Trigger and a particular Control Voltage in a regular rhythm. Later, with the advent of MIDI, it was possible to bring this task into the computer environment, and Sequencing software was developed.


  TRIGGER - A momentary surge of electrical current sent out of a cable which can be detected by a device at the other end of the cable and used to initiate an action in that device.


  VOCODER - A device which uses the harmonic spectrum of one sound to modulate the harmonic spectrum of another. The most common use of a vocoder is to use someone's voice speaking to modulate the harmonics of a sharp bass synthesizer tone. This was how the voice of Colossus was done in the movie "The Forbin Project". It has been used in a lot of movies and TV shows to imply a computer or robot voice, but such a sound has, to my knowledge, rarely been actually generated by a computer.


  VOICE - A set of circuits within a sound device which is responsible for generating the sound signal. There is no theoretical limit to how many voices a sound device can have. A Monophonic sound device has only one voice. A Polyphonic sound device has 2 or more voices. In the beginning of electronic musical instruments, most instruments were monophonic. In the mid-80's it became more common to equip a device with 4 or 8 voices. Nowadays, 64 or 32 are normal.