Waveshaping

Waveshaping is passing a signal through a fixed transfer curve — each output sample computed from the input value — to add harmonics without changing the oscillator's pitch.

The curve defines the result: symmetric curves add odd harmonics, asymmetric ones add even harmonics, and designed curves such as Chebyshev polynomials can target a specific spectrum. Sweeping the drive across wavetable frames bakes that brightening into the table, with the same caveat as wavefolding — nonlinear curves add highs that must be band-limited or oversampled to stay in tune.