The music heard in the game will also depend on the time of day; "Final Fantasy XIII: Lightning Returns" uses a day and night system - afterall the game is relying heavily on the concept of time. It is a brand new feature for a Final Fantasy game and perhaps it will be something Square Enix continues to use in future titles.
This is sounding more and more like Final Fantasy: Majora's Mask. Hopefully they pull it off as it will be awesome if they do!