Here is something quite interesting — iTunes Signature Maker. It peeks into your iTunes database then creates a “signature” based on what you listen to the most or rate the highest (via Alex McChesney).
The first time I had a go, I set it to be based on play count. But since I didn’t get round to putting my music collection on my computer until last spring, there is obviously a heavy bias towards this year’s releases and dirty downloads from before then.
I tried it a second (and third) time based on my ratings, but I guess it still takes play count into account because it chose almost exactly all the same songs! This is the first one are three by one band (including two different versions of the same song) and two by another band.
I think it’s very difficult to tell what’s in there — and I already know what’s in there! As such, I’m not sure it really “represents” my taste in music, because it mostly just sounds like a bunch of noise. Well, actually…
Update: My brother got good signatures by choosing more tracks but at shorter lengths. I created one using 50 tracks (one per artist only) and an average length of 2s, and I reckon it sounds all right. My second iTunes Signature.