Echonest has released a web service for mapping music identifiers across namespaces.
One of the problems faced by music application developers is the issue of ID translation. You may have a collection of music that is in once ID space (Musicbrainz for instance) but you want to use a music service (such as the Echo Nest’s Artist Similarity API) that uses a completely different ID space. Before you can use the service you have to translate your Musicbrainz IDs into Echo Nest IDs, make the similarity call and then, since the artist similarity call returns Echo Nest IDs, you have to then map the IDs back into the Musicbrainz space. The mapping from one id space to another takes time (perhaps even requiring another API method call to ’search_artists’) and is a potential source of error — mapping artist names can be tricky – for example there are artists like Duran Duran Duran, Various Artists (the electronic musician), DJ Donna Summer, and Nirvana (the 60’s UK band) that will trip up even sophisticated name resolvers.
We hope to eliminate some of the trouble with mapping IDs with Project Rosetta Stone.
For now they only support two identifier types, Musicbrainz’ and their own Echonest IDs. But
keep an eye out for the addition of commercial ID spaces that will allow easy mapping being Echo Nest IDs and those associated with commercial music service providers.
If I were a commercial provider I’d be looking in getting my own IDs into this API.