Something awesome is happening in the world of music and the web. But first, some primer.
Rdio is one of the few music subscription services that do a tremendous amount of things right, including having its robust Rdio API. For $5 a month, you can get all of the music you want, have collaborative playlists, share content to Facebook and Twitter, and keep up with what your friends are listening to. For $10, you can do all that and store the music to your phone for offline or higher quality enjoyment.