Composition in Q is only used at the end of episode 4 and only on a couple of text screens when Trent is feeling tired of all the fighting.
A game isn't abandoned just because the publisher goes under. Eg, it wasn't 'abandoned' just because Epic stopped publishing it because the developers stuck with the game and found another publisher. World Tree Games are still sticking with the guy behind Symmetry even though he's really useless and they're hoping to get it published again.
BTW Tyrian music in mp3/xm/midi/lds format can be found here:
http://members.iinet.net.au/~vannevar/tyrian/index.html
Alexander Brandon says it's ok to distribute the Tyrian music as long as you don't charge for it or anything. Any help with the unknown remixes would be cool too.
