Threesomes, a simple world, gives a good idea
of how this works.

Four Orbital Melodies

Eight little
bodies orbit around a larger one. Symmetrically for a while, until the
chaotic attractions of the rocks get the better of them and they swirl
seemingly randomly.

Four interlocking melodies are shared by the bodies, played on
piano, celesta, slow strings and a tuba!

2 Pyramids

Here the rocks get geometric. One note per rock, in successive
scales. One single body poised above. Changing the initial height by a
quarter inch ends up with a different melody.

Then the same world, with three bodies instead of one. They start out symmetric, and then
eventually the rounding errors kick in and they wander askew.

Grid thy Lions

Another geometric world, with four bodies moving around a grid. The
instruments are more "synthy," giving a bit of an ambient feel. This
one is also symmetric until the rounding errors add up.

PhaseX

"What would happen if we arrange the rocks in a big X?"

This is what
happens. The balls have two "phased" melodies attached -- almost the
same melody, but slightly different lengths, so they get out of synch
and combine with each other in interesting ways. <

PhaseX: 2 Mutations

Same world, but the center rock is a mutator. Every time a ball hits
it, it randomly changes the ball's mass. When this happens, the
simulation no longer runs the same every time. Here are two takes.