I just got a e-mail from the SevenCo-Op team leader (Sven Viking) stating the following:

The SvenCo-op site has been updated with five SvenCo-op-inspired MP3 music
tracks for use with the in-game MP3 player. Three are by (GIT)r-man, our
sound editor, and the other two are by Hetoreyn, composer of the Deep Angel
game/television series soundtrack.

http://www.svencoop.com/

Thanks,

Sven Viking
Team Leader
SvenCo-op for Half-Life
http://www.svencoop.com/