For the past 3 hours I have been cleaning up my desk and sorting out the papers I had printed out (yes, when I talk about spring cleaning, I really mean it)! Anyway, I was listening to last.fm, while cleaning up. I asked it to play similar artists to Mikis Theodorakis, who is an excellent Greek composer of hmmmm… “metasymphonic music” (the term is borrowed from Wikipedia). After a couple of songs of similar to Miki’s music, last.fm decided to play a necromantia song! Necromantia is a Greek black metal group. What is the similarity between “metasymphonic music” and black metal? Well both artists are Greek, but apart from that.. none I would dare to say!Last.fm FAQ on the “similar artists” functionality says:

The list of artists which you may see on an artist page as being “similar” is based exactly on our user’s listening habits. If a lot of users listen to Artist X, but also Artist Y and Z – Y and Z artists will become similar to X.

With a few added constants and other functions thrown into the equation to help make it more accurate, you’ll find that’s how Similar Artists are made.

The screencap follows: