Poots and I are pretty much on the same page here. Get the general idea working, then you'll probably want to get a bit hinkey with your suggestion calcuation. One thing I was going to suggest (in a later post) is that those genre and artist FK values that I mentioned might contribute to that score as well, and another point would be that tracking when songs entered and left the playlist might give you strong indications of musical taste too.

There are lots of things you can explore about musical taste, especially when you have decent samples of a listner population!

-PatP