Granular Playground

Granular synthesis cuts a sound into grains: short slices, usually 5 to 500 milliseconds long, each faded in and out by a smooth window so it starts and ends in silence. Played one after another at their original place, the grains rebuild the sound. Played from somewhere else, at another pitch or in a crowd, they make something new.

Four controls do most of the work. Size sets how long each grain is: very short grains blur into a buzz whose pitch comes from the grain rate, long ones sound like smeared copies of the source. Density sets how many grains start per second. Spray scatters where each grain reads around the play head, which turns a single moment into a shimmering cloud. Pitch resamples every grain, so the cloud can sound an octave up without playing any faster.

Because the play head and the playback speed are separate, granular synthesis can stretch time. Freeze the play head and a single syllable becomes an endless drone; let it crawl at a quarter of the speed and a phrase lasts four times as long at its original pitch. This is how granular time stretching, Paulstretch-style ambience and the famous Mutable Instruments Clouds module work.

When many grains overlap, their levels add up. Grains read unrelated parts of the sound, so they add up like noise: the loudness grows with the square root of the number of overlapping grains. This playground divides each grain by that square root, which keeps the level steady whether two grains or fifty are sounding at once.