FFVII

[Omega_Weapon]

What song plays when you first enter the Shin-ra building in the beggining of the game?

[crono_logical]

I would assume it's the very second track of the OST, Opening/Bombing Mission, whilst the first track plays before you start a game :p

[-N-]

He could also be referring to the Mako Reactor, in which case it's the 3rd track, or climbing up those stairs, in which case it's track 19, or track 9. Basically any OST title with Shinra in it. :p