Im playing the Windows version of X-wing. The one with redbook audio and all that... I already installed the music patch (music stopping fix) but I always have the impression the game is replaying the same track over and over. I played this game long ago and I remember it had more soundtrack between the tour of duty missions. Is that supposed to work that way?

Redbook basically means you have an audio CD with a data partition for the game files, which can be played as if it was a regular CD audio disc in most players. Given that some of the space on the disc is taken up by the game, that typically leaves only 40-50 minutes of music, which might be why you feel it's repetitive. I never owned the X-Wing CD version myself, so I don't know how it's supposed to behave, but it does sound somewhat like the other Redbook audio games I've played (Warcraft II: Tides of Darkness and Warcraft II: Beyond the Dark Portal being the ones I remember most vividly).

The original DOS version of the game used MIDI music, and actually composed a soundtrack on the fly using tiny soundbites (just a couple of bars here and there) from the Star Wars movie score, based on what was happening on the screen. The system for that was apparently removed from the CD versions, because "Redbook sounded better". Opinions on that vary dramatically. :)