The Long Run is a musical piece included in the Halo: Original Soundtrack.
This song is heard slightly before, and during, the "Rolling Thunder" section of Assault on the Control Room, when the player rides through the tunnels of Halo in a Scorpion Tank. It also plays at exactly the same point along the backwards journey through the same area in the level, Two Betrayals, in the large room after the blast door which explodes on opening. It is also heard on the level The Silent Cartographer while fighting a group of Stealth Elites and on the level 343 Guilty Spark after crossing the final energy bridge while escaping from the containment facility. In the level The Maw, it plays after John-117 destroys the engines of The Pillar of Autumn.
The piece is almost entirely percussive, with a few synth sounds in the background, which seems to resemble John-117 running. This makes it very similar to Drumrun. It also plays during the first part of the Warthog run on the level The Maw (which is probably what the title refers to), and consists of a repetitive drumroll which is designed to underscore the nature of the escape and to make the player feel a sense of urgency.