ilex said:
Huh? You mean putting HL (2?) cd in and starting the game produces new musics?
No no. Get your Half-Life (1) CD, put it in a normal CD player (hi-fi/stereo/walkman) skip track one (as its all the game files) then listen to it for a bit.
At least on Half-Life is where I first heard a couple of the tracks that are in the battle music.
I think I heard em on Buffy once too.