A Walk in the Woods
From Halopedia, the Halo wiki
A Walk in the Woods is the sixth piece included in Halo: Original Soundtrack.
The piece is dominated by synthetic woodwinds and a bass, which together start off solo before being joined by a steel drum. The woodwinds then begin to fade out, allowing the drums to begin dominating the piece with a pulsing, regular beat. Quickly, the winds join back in, re-establishing the melody of the piece. The melody fades out again, to be replaced by contrasting beats on cymbals; soon, the melody returns, now with the cymbals laid over it to lend a secondary beat to the piece. Near the end, the melody fades out for good, allowing the piece to gently conclude with cymbals sounding over the consistent pulse of the drum.
This track can be heard: