Spectral morphing

Spectral morphing transitions between wavetable frames by interpolating their spectra — partial amplitudes and phases — rather than blending the raw waveforms sample by sample.

Working per-partial lets the morph follow the harmonic structure of the frames, so brightness, formant shape, and phase relationships travel together instead of canceling. It is the engine behind smoothly evolving, vocal-like sweeps that would sound hollow if the same frames were only crossfaded.