About the Halo soundtrack...?

Question

There are three songs called "The 2nd", "The 3rd", & "The 4th Movement of the Odyssey"

1. Where is the 1st Movement of the Odyssey?
2. What do this songs have to do with Halo or Halo 2?

The song when you get into the banshee is called Follow...

Answer 1

the first movement is in the Arbiter level when you get in the Banshee (accompanied by a Phantom piloted by Tartarus) to hunt down the Heretic leader. i have no idea where the other movements are.
i guess the songs were created for the game like the rest of them.
Blow Me Away kicks @$$ at the end of the Gravemind(?) level