With this song, I drew on the experience I had when playing the game to decide what to do with it. When I first encountered Mamiya, I only heard the song for the briefest of times, only long enough to hear the A section and the variation on the A section.
Considering the song pops up twice in the game, I'd make the first instance of it here reflect my experience hearing the first instance of it in the game. The second time it pops up is during the final battle.
This song normally plays when you first encounter Madame Mamiya.