Selecta is an Amarok script that generates playlists of similar artists using Last.fm tags.
How it works?
First off, you need to have some music in your Amarok Collection.
After installing Selecta, you must update its index (go to Tools->Selecta->Update index).
It takes some time to fetch all the necessary data from Last.fm, about 10 minutes per 500 artists,
so please be patient.
Once the the indexing is finished, Selecta is ready to make some playlists for you.
Drop a couple of tracks into Amarok playlist and hit Tools->Selecta->Play.
Note: you should update Selecta's index whenever you add new artists to your collection.
How it really works?
You probably don't want to know...
If you are still interested, you may want to check out Selecta's SOURCE.