As the main theme, "The Promise" is heard several times. It has several arrangements and is also included in many tracks. The track itself is heard in-game at the title screen, and is the second track of the original soundtrack's first disc. A "prototype" version of the theme is included in the Final Fantasy XIII: Original Soundtrack PLUS. An instrumental version of "Sunleth Waterscape" has been released on the Final Fantasy XIII: Original Soundtrack PLUS album.