Yes, there's some pun with three/tree. I couldn't think of anything else. But basically, I've just spent the last hour procrastinating and I've come up with a nice D(ish)-HTML page that contains all my mp3 collection in a collapsable/expandable tree.
You can view it
here. And the source
here.
Now, it's too late to do anything substantial on eBusiness coursework, so I think I'll go to bed and read for a bit.