Morphing

In the context of a modular synth, morphing refers to an oscillator that can more or less smoothly change the shape of its output waveform – and therefore, the resulting sound – as you play it. This is usually the domain of digital oscillators which internally crossfade (or in some cases, switch) from one waveshape to another, although it is sometimes applied to analog oscillators that give you real time control over waveshapes.