I never liked co2's bg music, so I put in my own. It's the bg music from a flash game called "Lint" ([URL="http://onemorelevel.com/game/lint"]Click Here to Play]).
I backed up the music.ini for you. put the mp3 in c:/conquer online/sound and the MusicRegion.ini in c:/conquer online/ini.
nothing special, i just liked that bg music and went through a little effort to extract it from the game into a mp3 file.