Oh, wow! Sound-to-smell, um, sounds neat, pardon the pun! (Now I'm thinking about Brave New World and the scent organs they had that made "symphonies" of scents.)

I have been searching for the scent of Midgar....

For some reason what popped into my mind as my own scent-association for Midgar when you said that was BPAL's No. 93 Engine. Which I have not smelled in a while, come to think of it!