I've been toying with the idea of using physics simulations to generate audio.
First, imagine a audio in a circular loop, as on a record player. As the needle moves clockwise, the music plays. If the needle moves counter-clockwise, the music is played backwards. The faster the needle moves, the faster (and higher pitched) the sound.
Now, model the chaotic motion of a double pendulum, and use that as the needle that is driving the music:
It can also be interesting to use the data directly. Take a physics model of a double pendulum, and record the height (y) of the longer leg over time. Then, interpret that data as raw audio samples and play it!
Double pendulum as raw audio by jamonben
I inadvertently created a mashup while working on a related project, but it's not very good.