I just tested the first marine mission and either I didn't have any music (settings were on) or it didn't loop.
I'll restart the game again to check if it's a loop issues or if there isn't any music.
Anybody else have this issue?

EDIT: after further testing: no music at all (also tested the second level)

I have the same problem. No music.

hmm maybe not a widespread issue or nobody is playing SP. If nobody has a solution in a couple of hours I will just contact support.

The original game came with a second CD that has the music on it, you usually played it in the background if my mind serves me right whilst playing the game. Need to look in the manual and see what it says, pretty sure though you have to have the disc in the drive for it to have music playing.

I have a digital copy from gamersgate and it has the music. I'll check the GOG version later.

my steam version has music too so this should definitely have it (since steam does zero effort for this, see quake series)

It probably needs adding to the game. I noticed on the Twitch Stream yesterday there was music playing in the background

That is correct: there was music during the stream.

I have to head out for a half our and take the dog out, I will look into it when I get back in and see if the CD can be ripped and then MP3's added to a directory or something, there is bound to be a guide on the net where the files need to go

Awesome, thankyou, the music really adds to the tension of the game

I can confirm all is fine now! Thank You. As Iain said: it's a very important part of the game.

So, how to add music in game? I didnt get it

Yes, Music is in game - but how to take it out to my player))