(1) Tue Aug 26 2008 17:27: If you're up on your Anathem gossip you'll know that the book (or, at least, the Advance Reader's Copy) comes with a CD of nice acapella chant music. What has been somewhat obscured by descriptions of this music is that each piece doesn't just have a fancy math-related title, it actually is a piece of math. Usually a description of a cellular automaton, or a proof represented in some bizarre musical Gödel-encoding. And what I didn't know until Mirabai emailed me is that the scores for these songs are being published by their author, David Stutz.
He also explains some of his pieces in more detail on his blog, like this representation of the Adrakhonic Theorem: http://synthesist.net/music/2008/08/mohr-mascheroni-math-in-the-music-of-anathem/