Partials

Partials are the individual sine-wave components that sum to make a sound's spectrum — the umbrella term that covers harmonics plus, for non-periodic sounds, inharmonic components.

An FFT of a wavetable frame reports one magnitude and phase per partial, and an additive editor lets you sculpt a frame by drawing those partial levels directly. A frame of N samples can hold at most N/2 partials before running into Nyquist, which is why short frames put a hard ceiling on brightness.