ShadowOwl: The Steam version received a patch abpout two weeks ago which fixes the N64 soundtrack. It's no yett on GOG...
http://steamcommunity.com/games/405830/announcements/detail/1435937463333425336
Hello Dinosaur Hunters!
Just a quick announcement to fill you all in on the 166MB update that recently went out.
We listened to your responses, and decided to go back and re-visit the N64 music recordings that were made for the original release. They have been rebalanced and are now much louder!
We hope you enjoy them.
Daniel,
Turok 2 Producer,
Night Dive Studios.
ShadowOwl: I contacted the devs on Steam and according to them it is already on GOG. It's part of update 4 here. I guess it was never added to the changelog.