Yeah this piece was a huge piece of inspiration for me when I was learning Csound. I actually had a chance to ask BT about this particular piece once and if the rumors were true about it being all done in Csound. The guitar riff you hear halfway through the piece is actually sampled and played via the diskin opcode. Other than that, all Csound. Still a very impressive feat, especially considering the fact that the piece itself was originally mixed in 5.1.
Nice! I'd wondered about that guitar, it sounds impossibly real to be pure Csound. Thanks for the insight. And yes, I had the opportunity to listen to the whole album on a decent 5.1 system at uni a while back and it's pretty spectacular.