Mathematical constraints can help create beautiful music. Two minutes in you'll hear Vi Hart's "self referential string quartet" in which each instrument plays its own name - using the binary representation of the ASCII value of each letter. And she goes from there, in one of the most inventive Gel talks ever.
More of Vi Hart's brilliant explorations into math and music are at her site: vihart.com
More Gel videos: gelconference.com/videos/