Alright so i saw the video of TotalBiscuit, as one of his last comments he clearly said he couldn't find the music files. Therefore i grabbed my ancient old CD and just copied the music files off added them to the openRa and they automatically work.
it should be somewhere in "C: /(yourname)/My Documents/OpenRa/Content/d2k/Music"
Download it here:
http://speedy.sh/QaT3Z/Music.rar
(click on the Music.rar at the top of the screen and it starts downloading.)
The winRar contains
AMBUSH.AUD
ARAKATAK.AUD
ATREGAIN.AUD
ENTORDOS.AUD
FIGHTPWR.AUD
HARK_BAT.AUD
LANDSAND.AUD
OPTIONS.AUD
PLOTTING.AUD
RISEHARK.AUD
ROBOTIX.AUD
SCORE.AUD
SOLDAPPR.AUD
SPICESCT.AUD
UNDERCON.AUD
WAITGAME.AUD
17 files.