From Halopedia, the Halo wiki
This article is about the soundtrack. For articles of the same name, see Fortress.
Fortress is the fourteenth track (Disc 2 Track 7) included in Halo: Reach Original Soundtrack.
The track is composed of a heavy melody, in which the brass instruments play each note in shortened duration, while accompanied by percussion.
The music does not appear in any full-length format in-game. However, the opening and ending of the music may play during Invasion, whenever Elites enter the second phase or third phase