Please, name this common Final Fantasy song...?

I dont know what it's called, but it's used in a lot of the songs. When you boot up final fantasy 7 it plays (not the theme song) and when you get a game over in final fantasy 7 it plays towards the end of the game over screen. It's a really simple melody that starts with a low note, slowly builds up maybe a half step at a time for maybe one or two octaves, and then goes back down. Ive looked everywhere and cant find it. it was used in some earlier games and I think it was even a musicbox song in the advent children movie....