Check out MiJay, the “Facebook for Music” app. See a live view of what your friends are listening to on their device and lists of all of their music, albums, artists, genres, and songs. See if you have the same musical taste – do you have two songs in common between your libraries or five hundred? Look at the history to see what your friend was into last month, and last year. And if you spot a song that you should own in your own digital library, you can purchase and download it directly from the app.