http://www.symphonyofscience.com/
Description taken directly from the site:
"The Symphony of Science is a musical project headed by John Boswell, designed to deliver scientific knowledge and philosophy in musical form. Here you can watch music videos, download songs, read lyrics and find links relating to the messages conveyed by the music. The project owes its existence in large measure to the classic PBS Series Cosmos, by Carl Sagan, Ann Druyan, and Steve Soter, as well as all the other featured figures and visuals."
This stuff is great. This isn't really anything I'd normally listen to but the person who made the videos does a phenomenal job of making usually boring documentaries into relatively nice sounding music. If you have an inclination towards the universe, space exploration, etc.. this stuff is really, really awesome.
My favorites are "The Poetry of Reality", "A Glorious Dawn", "Our Place in the Cosmos", and "Ode to the brain!"