Brothers in Arms

Brothers in Arms is the third track of the Halo: Original Soundtrack.

Overview
The track opens with a synthetic drum beat; then, the melody of the piece begins on the flute. In the middle of the piece, the melody segues over to strings, who continue the piece's main motif an octave lower. They are shortly joined by a fanfare on synth organ. In the end, the drums fade out, allowing the strings and flute to slow the tempo and bring the piece in for its serene conclusion.

Appearances
The soundtrack can be heard:
 * The ending is heard in the main menu of Halo: Combat Evolved
 * In the opening and closing cutscenes of the level The Pillar of Autumn.
 * Twice during the level Halo; once during the Covenant's last attempt to eliminate the first group of survivors, and again on the Covenant's attempt to kill the very last group of survivors.
 * Four possible times during the level The Truth and Reconciliation, once outside the ship, once in the shuttle bay if most, if not all, of the Marines are dead, once near the brig where Jacob Keyes is being held, and once in the ending cutscene.

Reorchestrated versions
The track is reorchestrated into the following:
 * Ending of this track was reorchestrated into the ending of Great Journey in Finale of Halo 2: Original Soundtrack.
 * Follow Our Brothers of Halo 3: Original Soundtrack.
 * Brothers in Arms of Halo Legends: Original Soundtrack.
 * Bravery, Brotherhood of Halo: Combat Evolved Anniversary Original Soundtrack.

Production notes
Brothers in Arms started out in early 2001 as "battle sketch", a piece played on piano by Martin O'Donnell. He later added percussion and brass to the arrangement, alongside strings, a choir and woodwind instruments. O'Donnell continued to work on the song in some form or another during the production of Halo 2 and Halo 3, ultimately recording the final song in 2007.