3 History

3.1 Swarm Synth, the series

Swarm Synth is a series of interactive audiovisual instruments that I have been building since 2018. In each of them a digital swarm becomes sound. Its agents move by Craig Reynolds' Boids algorithm, in which each agent follows three rules, looking only at the neighbours it can perceive:

• Separation: steer away from neighbours that come too close, so as not to collide.
• Alignment: steer toward the direction in which the neighbours fly.
• Cohesion: steer toward the centre of the neighbours, so as to stay with them.

No agent knows the whole, and there is no leader, yet out of these three rules the swarm organises itself — into flocks, streams, turbulence — and its patterns play the music.

The visitor does not play notes but rules. Three sliders — separation, alignment, cohesion — set how far the agents perceive each other for each rule, and the swarm answers with order or disorder, consonance or noise. The control is indirect, but it can be learned: as one practises an instrument, one can practise leading the swarm toward a sound.

The series asks how sound can be organised beyond the conventions of harmony — not by a composer's intuition but by the logic of a self-organising system — and it works with the plainest electronic sound there is, the sine wave.

Swarm Synth V – Emergence (2026), the fifth version, makes emergence itself audible: every flock that forms sings its own drone, every meeting of two agents rings a short note tuned by its flock, and a flock flying straight across an invisible grid keeps time. V is an instrument to be played live and also a tool for composition: written scores reproduce a performance exactly and are rendered to video.