The Gun Pointed at the Head of the Universe is the 8th track included in the Halo: Original Soundtrack.
It is heard in almost every level of Halo: Combat Evolved, starting with the level Halo, where the song is played near the underground Forerunner structure and when battling the final Covenant with the last group of survivors. In The Silent Cartographer, it plays when the player comes to the Silent Cartographer building for the first time. In the level Assault on the Control Room, it plays for a few seconds when you first enter a Scorpion, it plays when you encounter the tunnel entrance guarded by two Wraiths, and it also plays when you battle the Plasma Rifle-wielding Zealot Elite. In the 343 Guilty Spark level, it plays when you are leaving the Forerunner construct and fighting Flood in the swamp. In the level Keyes, it plays when you first enter the shuttle bay immediately after Captain Keyes orders you to pull out. It also plays in the level The Maw, when John-117 blows up the engines of the Pillar of Autumn.
It is composed nearly entirely of percussion, only having a deep bass note around 1:28 and some vocals at the end of the piece. The rest of the sound is produced by a combination of drums, auxiliary percussion and hand-clapping, which is usually unheard of in many tracks written for Halo.
- The name of the song is most likely in reference to the Halo Installations.
- The name is also a chapter at the start of the level Two Betrayals in Halo: Combat Evolved.
- This song was remixed into part of Heretic, Hero in the Halo 2: Original Soundtrack and on the Halo 3: ODST Original Soundtrack song More Than His Share at the part Into the Breach.
- This song is quite similar to Drumrun also on the Halo: Original Soundtrack.