Mike Doughty, a singer/songwriter (formerly of Soul Coughing) and now an indie artist, was asked by Yahoo Music to write a song celebrating 10 years of the iTunes Music Store.
It's a catchy number, and will certainly be stuck in your head after watching the video. Mike also gets bonus points for using Cassingle™ as though it is still an actual word. It's a self-shot video, mostly likely from a built-in iSight camera (I am guessing -- at the end of the video you can hear the "Submarine" system beep pretty clearly before he stops recording, but it could be a third-party webcam instead).
Oddly, this song is not yet available on iTunes, or anyplace else that I can find. In the meantime, the video is below, and fun to watch (or just let it play in a background tab as you tap your toe).