Halo Soundtrack question

Ive heard this same tune throughout halo 4. I have the soundtrack and it is not on there. (Not the physical copy) the song is played a lot in episode 9, the very end of episode 8, and seems to be the theme for the mission forerunner in the campaign if im correct.

It sounds so mysterious and really sets the ancient forerunner mood.

If anyones in the same boat as I am maybe you can help me. Thanks.

Check here to see if the music you’re talking about is there. If it’s not, you might have to wait until Vol. 2 is released.

Found it! Its buried and forgotten. When will a volume 2 be out you think? Whered you get these tracks?
And thanks!