Following up to my post from yesterday, I found another funny last.fm calculation, the AEP Calculator.

You just type in your username and based on the top 50 artists in your profile, it will tell you how diverse your music taste is. If you are over 4 you’re very diverse, under 0 means you’re kind of obsessive about your top artists.
See the site for more information on how this index is calculated.

My my AEP