Electronic Music Interactive, 2nd edition

Glossary

partials: frequencies in a waveform that are higher than the fundamental. The frequencies may be harmonic or non-harmonic.
period: the time-span occupied by one complete cycle of a waveform.
periodic waveform: a type of waveform whose pattern of fluctuation repeats continuously.
phase: used to specify a particular point in time on the waveform, or to compare the relative position in time of two waveforms. Phase is described in terms of degrees from 0 to 360 degrees, 90, 180, and 270, marking the 1/4, 1/2, and 3/4 points, respectively.
pink noise: a common type of noise consisting of all audible frequencies of equal amplitude randomly distributed between any octaves.
Pitch bend message: a type of two-byte MIDI command that sends information on a specified channel about how the pitch of a note or notes on the corresponding channel should be changed over the course of time.
Poly mode; Omni Off, Poly: a MIDI mode where an instrument is enabled to respond to one note or more than one note at a time and only on the single channel on which the message is transmitted.
pulse wave: a waveform where the harmonic spectrum is dependent on its duty cycle in that the only harmonics missing correspond to the duty cycle. If the duty cycle is 1/3, then every third harmonic is missing (3, 6, 9, etc.), if the duty cycle is 1/4, then every fourth harmonic is missing, and so on. The relative amplitudes of the harmonics are expressed by the ratio 1/harmonic number. Also called a rectangle wave.
rectangle wave: a waveform where the harmonic spectrum is dependent on its duty cycle in that the only harmonics missing correspond to the duty cycle. If the duty cycle is 1/3, then every third harmonic is missing (3, 6, 9, etc.), if the duty cycle is 1/4, then every fourth harmonic is missing, and so on. The relative amplitudes of the harmonics are expressed by the ratio 1/harmonic number. Also called a pulse wave.
regeneration, resonance, emphasis: a parameter available on many filters which permits the frequencies at and around the cut-off frequency to be given greater prominence.
release: the final stage of an envelope, but may have other meanings depending on context.
resolution: the number of discrete amplitudes a digital recording or digital synthesis system can represent; resolution is expressed in terms of the number of binary digits (bits) used to represent each amplitude value. 8-bit (256 values) or 16-bit (65,636 values) are the most common.
response curve: a graphic depiction of how a filter, synthesis module, or other electronic device responds to a signal.