Movement

From Halopedia, the Halo wiki

200px Movement is a song included in the Halo 3: Original Soundtrack.

It starts with a choir melody. At 0:12, drums and orchestra joins in and gets louder and louder. The song swells and abruptly ends. This plays randomly in the Main Menu of Halo 3.

It runs for 0:26.

It should also be noted that this song can be heard in the Starry Night announcement right when the Master Chief throws the Bubble Shield.