Petri Nets as a Music Sequencer

gist

Stackdump shows how one Petri-net primitive can drive every layer of a deterministic browser music generator. Token rings produce Euclidean rhythms, mismatched lengths create polyrhythms, and separate control nets schedule song sections and Auto-DJ transitions. Replacing long chains with token countdowns shrank a three-minute project from 22 MB to 242 KB. Because execution state stays inside the net, the running diagram also serves as the reproducible state model, scheduler, and debugging view.

ideas

• Use one state primitive across layers. Notes, rhythms, song structure, and transition commands all become tokens moving through nets.
• Let topology generate musical structure. Hit placement around a ring produces Euclidean rhythms, while unequal ring lengths create polyrhythm without a separate timing system.
• Represent delay as quantity. A countdown place holding many tokens replaced long chains of mostly empty steps and cut the project representation sharply.
• Bring boundary events into the scheduler. Encoding Auto-DJ transitions as control nets removed races between the worker and main-thread timers.
• Make runtime state visible. The same diagram that executes the track reveals stuck tokens and phase errors while preserving deterministic replay.

quotes