In today's installment of cool things I don't completely understand, we have moonbell, an automated music generator from the Japan Aerospace Exploration Agency that converts lunar topographical data -- collected by the Kaguya explorer during its orbit around the moon from 2007 to 2009 -- into music. It automatically begins orbiting and playing music when you visit the site, and if you click and drag the white square on the moon, you can change the orbit and the song.