The Whitney Music Box is a wonderful example of Process Music. The audio generated is musical in nature, and the process itself is obvious thanks to the simplicity of the animation. Each of the 18 variations have their own distinct qualities, showing the versatility of the instrument and of the sound spaces it creates.

Whitney Music Box is based on John Whitney’s motion graphics, realized by Jim Bumgardner, aka KrazyDad.

From the description:

in three minutes, the largest dot will travel around the circle once, the next largest dot will travel around the circle twice, the next largest dot three times, and so on. the dots are arranged to trigger notes on a chromatic scale when they pass the line

Thanks to PAgent of PAgen’ts Progress for the link.