You certainly recall OeufMayo's Transcramble. I tried to apply the same technique to music. You can read about the results here: Automatic Music With Perl.

<milk> larsen, I am quite struck by them.. from listening to them you can tell they are meant to have musical structure, and they sound like they are intentionally musical, but they contain no coherent musical "thought"
<milk> if you know what I mean?
<milk> they are like a sentence which is grammatically correct, but has no meaning because it is nonsense

Some more points about this stuff...

• Given a girl interested in modern music, Duchamp's art and so on, you could even try to impress her...
• I think we have found the first real-life example of use of Tie::Hash::Cannabinol :))
• You could try some kind of automatic jazz improvisation, feeding the program with a MIDI file containing a lot of scales and phrases.

Update: Here a direct link to the code.
Update: I received an interesting link about generative arts: Generative.net.