He's singing about the Dark side of the sun :)
The wallpaper version is at the preceding link.
Today's Gratitude Item: Finally figuring out how to top up my mom's cellphone online. The website concerned was extremely difficult to figure out, and the error messages were not at all clear. Then again, that is what I have come to expect from big companies. They should spend less time on their marketing and more time on making their website easy to use.