A sound synthesis technique whereby one oscillator’s cycle is synchronized to that of a second. This forces the waveform of the slave oscillator to restart its cycle each time the master crosses the zero-point. As a result, the fundamental of the slave is the same as the master, but the waveform is radically changed. The pitch of the controlling oscillator is not normally added into the audio mix, but can be shifted by pitch-bend, envelope, aftertouch or an LFO, producing substantial changes to the harmonic content of the slave oscillator, but without changing the fundamental pitch as does ring modulation. Instead, the higher harmonics around the pitch of the slaved oscillator are emphasized, producing a very hard edge to the tone.