while i think that songs like "Nemesis" "Awakening" "Revival" "Blue and Green" and "Requiem" where pretty good, but i admit, i got an immense chill when the song that played after the didact's ship reached the UNSC Research facility located near the Halo installation and it just gave the game alot of life for those brief few seconds.
I'd like to see the original Halo Theme, Last Spartan, Ghosts of Reach, One Final Effort, and multiple tracks from Reach (can't think of them at the moment, sorry), and some of ODST's songs, bring some of those back or model after them, give us that instrumental feel, make the music make the game come back to life, the most that Halo 4's Soundtrack did to me was just keep me awake and up beat, but it didn't give me the feel that the original Halo Soundtracks composed by Martin O'Donnell did. those where what helped make Halo special, ontop of it's storyline and big maps to run on as well as how big the campaign levels where and the things we could do on them. And the Easter Eggs