Part 79: Granular Synthesis

Part 79

Granular Synthesis

Every synthesis method we've seen ties pitch to playback speed. Granular breaks the link. Time-stretch without pitch change, pitch-shift without time change.

How It Works

A grain is a tiny snippet of audio (5–200 ms), shaped by a fade-in/fade-out window. Layer dozens per second and you get a continuous texture. Because each grain is independently pitched and positioned, granular decouples pitch from time: stretch without dropping pitch, shift pitch without changing speed.

Controls

Position: Read point in the source (0–100%)
Speed: How fast the position advances. 1x = normal, 0 = frozen
Grain Size: Length of each snippet. Small = texture, large = recognizable
Pitch: Playback rate per grain. 2x = octave up, independent of speed
Density: Grains per second. More = smoother, fewer = individual events
Spray: Random scatter around read position. High = ambient cloud
Window: Fade shape per grain. Hanning = smooth, Rectangle = clicks

Position0%

Size50ms

Density20/s

Speed1.00x

Pitch1.00x

Spray0%

Window

References

Sound On Sound: Granular Synthesis, comprehensive overview
Wikipedia: Granular Synthesis, theory and history
Iannis Xenakis, pioneer of granular composition
Cycling '74 Max, where many granular techniques were prototyped
Robert Henke: Granulator, Ableton's granular instrument