The MusicBrainz C Library by MusicBrainz is a client library to assist developers in creating MusicBrainz disc IDs and freedbs from audio CDs. The MusicBrainz database contains a huge amount of music metadata, which is maintained by the MusicBrainz community.
Major U.S. music festival Lollapalooza is catering to hackers with its new Lollapalooza API and a contest. Even though music may be of interest to those who program, music festivals normally don't fall under our purview here at ProgrammableWeb. We're excited that this acclaimed music festival is making its data available to the public this year so developers can build applications involving their scheduling and artist info.
Microsoft's latest version of its search API (our Live Search API Profile), which was released last November as a public beta, seems to be gaining quite a bit of momentum. According to a recent post on the Live Search Blog, the API is serving more than 3 billion queries per month, more than 5,000 applications to use the API, and queries from third party sites account for 80% of the API's query volume.