AVEE'S PROFILE

You could do it with Terrain ID recognition I guess. If one continent is full of snow tiles only, have a Parallel Process event play the snow music. You might also make tile duplicates in your tileset in order to have different musics play on different areas that have the same terrain type.

Oh come on, I said I hated Vocaloid so other people don't think I actually dig it. Tastes aren't insults. You might hate sushi while I love it and I wouldn't be insulted :P

Anyway I can't help you much more than that, I don't know any Vocaloid songs. I know there was a live concert with the characters' projections on transparent screens, you can watch it on youtube. My suggestion was that you search for the songs of the one ponytail girl, Akita Neru or something like that.
Good luck.

http://www.pacdv.com/sounds/people_sounds.html
Help yourself ^^

Search "vocaloid characters" in google images, identify your singer and then browse her songs on youtube.
(I hate Vocaloid btw)

There is no reason for a demo to end on a cliffhanger, particularly the type of demo being referred to here.

There is if the developer wants to maximize chances of players looking forward to the next release. That's up to Camupins to decide in this case.