Follow (1st Movement of The Odyssey)
From Halopedia, the Halo wiki
The 1st Movement of the Odyssey, also known as Follow, is a musical piece performed by Incubus and included in the Halo 2 Original Soundtrack. It is famously known as the music that plays during the Arbiter's pursuit of the Heretic Leader during The Arbiter, although the game version played is without vocals.
The track has a percussion beat, as well as cymbals used at various points. The main sound of the track is played on an electric guitar. The guitar is played using individual notes rather than chords. The remaining major sound of the track is comprised of vocals, with parts similar to the opening of the Halo Theme and well as common repetition of the word "Follow". It also has similar non verbal vocals at different lulls in the song, and at the very end.