Another approach: http://www.youtube.com/watch?gl=CA&hl=en&v=ipzR9bhei...

This is _Hacker_ News, we want to know _how_, not _what_ ;-)

I'd have to guess he used some kind of fourier analysis.

Yep...actually a pretty trivial example of Fourier analysis.

Well I guess I have to post the one I did a while back: http://www.youtube.com/watch?v=P6nkqqOZKpY

I recorded the music on a midi keyboard then wrote some perl scripts to read the midi file and generate POV-Ray scene files to go along with it.

Two YouTube videos, and nothing else?