Requiem was one of the final pieces written by the famous composer Mozart. It's title meant "Mass (or song) for the dead". This could be possible hint to the background of the planet. The name could imply that it is a a storage area (mass) for the Flood (the dead re-animated), or that it is a home for an forgotten civilization for a race (Forerunners or Precursors) that was thought to be dead.
Any ideas from you?