At its core, to oscillate means to vary back and forth in a repeating pattern. The main sound generator in a modular system is called an oscillator because its output varies up and down (oscillates) in voltage in a repeating pattern. This pattern is referred to as its waveshape (such as a square wave, that alternates between high and low voltages); how fast this pattern repeats is called its frequency or pitch.
An acoustic instrument equivalent of an oscillator is a string that vibrates back and forth on a guitar, a drum head that vibrates up and down, or the vibrations in the reed of a woodwind instrument. The vibrations of a modular synth’s oscillator just happen with electricity going down a wire rather than a physical object vibrating in air. (Eventually this electricity is routed to a speaker, which then vibrates the air with the same pattern sent to it over a wire.)« Back to Glossary Index