Rundas-mae

Track_4, as named by the music player, is a theme from Metroid Prime 3: Corruption.

Description
Track_4 is heard in cutscenes where Rundas interacts with Samus Aran. It is first heard on Norion when Rundas informs Samus that she can remotely command her Gunship, and it is heard again after Rundas rescues Samus from Meta Ridley. Track_4 is heard for the final time when Rundas dispatches some Space Pirates at Bryyo Fire, just before he battles Samus. Essentially, it serves as Rundas's leitmotif prior to his more iconic boss theme.

Track_4 is not included in the Soundtrack Gallery. However, it was available on the music player on the UK Corruption website.

Track_4 largely consists of a militaristic drumbeat and a male choir, although an electric guitar and ambient noises are also heard at times. The choir proudly sings a recurring melody from the Corruption soundtrack, which is also heard in the themes of Gandrayda and SkyTown.

Track_4 can be heard here:

Trivia

 * Rundas is the only one of the three Bounty Hunters fought in Corruption who has a separate theme for encounters outside his boss battle. Gandrayda's encounter theme is an abridged version of her battle theme, and Ghor has no encounter theme.