From Halopedia, the Halo wiki
Haven the sixth track in Halo 4: Original Soundtrack.
The track opens with a theremin and synth effects before strings enter with a suspenseful melody, joined by female vocals, horns, and twinkling effects. The cascading melody builds up to a grand climax, with the different instruments cascading over each other, then fades out.
The track can be heard:
The track was inspired by the Forerunner structures in Requiem, shown to composer Neil Davidge by 343 Industries during their first meeting in December, 2010. Davidge noted that the track pays homage to various science fiction musical scores, including the Blade Runner soundtrack by Vangelis and the soundtracks for The Day the Earth Stood Still.