Most electromechanical and electronic organs use subtractive synthesis, as do pipe organs. Indicators rich in harmonic partials (such as sawtooth waves) are picked through the performer with the keyboard and blended and shaped acoustically by filter circuits that simulate the formant, or resonant-frequency, spectra—i. William Basinski’s prolonged perform Disintegration Loops https://www.youtube.com/watch?v=O0pLXQTzDIw