Music. It comes in all kinds of goodness...

[oddbatt]

Violin
http://www.break.com/index/amazing_fiddle_player.html

Theremin
http://www.youtube.com/watch?v=Xn4TgYkqdi8

Reactable
http://www.youtube.com/watch?v=0h-RhyopUmc&mode=related&search=