This is a graph representation of the similarity relationships derived from the database of Last.fm. The circles (vertices) on the left hand side figure are bands, musicians, composers, whatever you will find in the Music section of the site. Lines (edges) connect similar artists.
This map and the data behind it were compiled by Dr. Henry Niman, a biomedical researcher in Pittsburgh, Pennsylvania, using technology provided by Rhiza Labs and Google. The map is compiled using data from official sources, news reports and user-contributions and updated multiple times per day.