Last.fm collection of C++ libraries by mhx includes algorithms, abstractions, configuration, object oriented shared object loading, template meta programming, and XML parser among other resources that aim to facilitate API interaction. With these libraries, users can access albums, artists, and playlists. Installation instructions available.
The legendary Billboard charts are now open for mixing, not by DJs, but by programmers. Billboard, a service of Nielsen Business Media, has a new API that lets developers search and read information from all the Billboard historical charts. The initial offering is its Chart service and later on Billboard will "roll out the Artist and Track services to add even more depth and perspective." the API is a simple REST interface that developers can send HTTP GET requests to in a familiar service/version/resource fashion. We've added a new Billboard API profile with details.
Our API directory now includes 51 audio APIs. The newest is the Umano API. The most popular, in terms of mashups, is the SoundCloud API. We list 27 SoundCloud mashups. Below you'll find some more stats from the directory, including the entire list of audio APIs.