From Music Hack Day
Enhances the current Spotify integration on Sonos by providing playlisting and similar artists, via Echo Nest APIs; and providing upcoming concert listings, via Seatwave APIs.
Ron Kuper, Sonos
 About the hack
Adds a 2 new nodes to every artist browse - an "artist playlist", and "related artists". The former uses the Echo Nest playlist API to create a play list based on the artist. (Note tracks on this playlist are played using Rdio behind the scenes because Rosetta doesn't yet support Spotify IDs.)
Related artists uses Echo Nest's artist APIs, and runs a search against Spotify in the back-end to map the related artists back to real IDs that are browseable and playable.
 What APIs, tools or kit did you use?
Sonos Music API, Spotify Metadata API, Echo Nest, Seatwave