Magic Playlist - Get the playlist of your dreams based on a song
Music-Map - The Music-Map is the Tourist Map of Music, part of Gnod, the Global Network of Discovery.
Spotalike - Spotify playlist with similar songs, according to Last.fm
Tempso - Finally a place for classical music online!
Playlist Machinery - Tools that help you create & organize your Spotify playlists
Because Recollection - An interactive experience looking back on 10 years of music