GOGOAM generates music by mapping geometrical properties of shapes into notes. At the heart of the system there are shapes. The shapes encode pitch and volume over time and by that embody melody reefs or loops. Shapes cannot create sound on their own. They need a playback device. A playback device define an instrument and a rythme. The combination of a shape and a playback device (instrument) creates the melody loop.
The user can control the mood of the music by dragging shapes on and off the instruments. At any time, if he feels he got crappy shapes that don't sound good at all, he can use the recycle portal to generate a new random shape (and melody).
Source code: github.com/galsasson/gogoam