Check this demo out, it is LESS than 64KB in size (no kidding).
Created by a bunch of "scene" guys back in 2000,
and not surprisingly won the first place at The Party 2000.
The demo is attached, also attached is the tool to extract the music if you like it

(warning, when the music is extracted and generated it becomes a wooping 100+MB wav file, you have been warned)
Now download the attached demo, and the music extraction tool.
Play the demo. (it lasts around 16minutes or so then end/quit)
Extract the music, listen to it while you read how they did it.
at: http://www.theproduct.de/idea.html (to go between pages click in the topright menu)
Then come back here and post:
W O W !!!
Which is all I can say for the lack of another word.
(Brilliant is a given so I wont say that
