Last of the Brave
From Halopedia, the Halo wiki
Last of the Brave is the fifth track (Disc 1 Track 5) in Halo 3: Original Soundtrack, and plays during the Halo 3 campaign level Crow's Nest. It is composed of Last of the Brave (0:00-1:43), Cold Logic (1:43-2:22), and Cool Temperament (2:22-3:59).
Last of the Brave (1:43) begins with an reorchestration of Brothers in Arms (from Halo: Original Soundtrack), albeit omitting the high strings, woodwind and choir, thus leaving the brass, percussion, and low string sections. After reaching the climax point of the Brothers in Arms melody, the piece then continues on with only the drumbeat, with the percussion gradually becoming more and more elaborate. A high string note fades in, before a drumroll brings the piece to its conclusion. The piece plays as John-117 enters the cave adjacent to the operations center and is told to go to the hangar.
Cold Logic (0:39) uses a similar synth effect to Ancient Machine (from Halo 2: Original Soundtrack, Volume 1), with chromatic synthesised notes in the background. Low strings take over for transition to the next piece. The piece plays when John fights Yanme'e outside the operations center.
Cool Temperament (1:37) begins as the previous piece fades out and a new low-string melody is introduced, which is then joined by low tempo percussion, continuing on until the end of the piece. The piece plays after the John-117 leaves the operations center for the second time and fights the pack of Jiralhanae led by a Chieftain.