"Chaos Shrine" is the background theme for the first dungeon, the Chaos Shrine, and the Sunken Shrine. An arrangement of this theme, "Sunken Shrine", is the background theme of the final dungeon, the Chaos Shrine of the Past, and unlike what its name might imply, it has no relation whatsoever to the aforementioned Sunken Shrine area.
Both tracks can be used as the default background theme for battles including Warrior of Light or Garland, or any battle with the Chaos Shrine as the arena. However, the downloadable NES version of "Chaos Shrine" will only be automatically selected for Arcade or Quick Battles.
An arrangement of "Chaos Shrine" appears as a Battle Music Sequence for the final boss, fought when the player acquires 10000 Rhythmia. It is, notably, the only original remix playable as a music sequence in the game.