[youtube http://www.youtube.com/watch?v=cU-eAzNp5Hw] Update (3/24 10:45am): For a limited time, Loopy HD has been discounted to $3.99 (50% off).

Jimmy Fallon’s MacBook may have mysteriously lost its illuminated Apple logo but it seems his love for Apple products hasn’t wavered.

Last night he teamed up with one of America’s biggest rock legends, Billy Joel, to create a doo-wop song using an iPad Air connected to two Bluetooth microphones. The duo utilized the iOS app, Loopy, to create a continuous background loop of their singing as a foundation for the song.