Generative Music
Music generated or assisted by algorithmic means, often with the environment playing a large part in the algorithm.
Kepler's Orrery Gravity-based n-body simulator. Music plays when worlds collide.

Originally an open-source java project,
Now available as an iPhone app

  A room that listens to you, detects notes, and composes music based on what it hears. Haunted Garden
evolve A genetic algorithm modifies the strategy used to harmonize a theremin linked to a 15 foot tall double helix connected by Ruben's tubes. (It was targeted for Burning Man '07; we didn't complete it, and the generartive music software ended up driving a theremin mounted in a stuffed bunny's ears)   Autonomous spherical robots with generative music system: each orb composes music as it rolls; compositions are constrained to be in harmony with each other as orbs near each other. Orb SWARM
Alea A random composition generator.
Not yet released by itself, it ended up in Heavens Speak and in the Kepler's Orrery iPhone app.
  Music made from Conway's game of Life.
(At some point I'll document this...).
Life Music
PolarBall (CaCO3.60) Music generated from the position and velocity of marbles rolling around a curved surface. (Collaboration with Matt Bell of Reactrix technology.)   Codons from streams of nucleotide letters (ACTG) entered generate two intertwining melodies. DNA Notes