Alright, so do we want to put on our thinking caps and speculate how these songs might be used in the game? Here are my best guesses (note that best does not necessarily mean good, or accurate):
The Broken Mirror-Sounds rather depressing. Could be used in Erik's scenes early, or maybe Katja's.
Nebulous-A really fun piece, probably a general school scene, but maybe associated with Annaliese's route.
Listless Reminisce-This sounds like a reworking of Recollections, so this could very well be the title screen piece.
Be Green-A reworking of December's Greetings I think. This sounds like it could just be a fun song for general school scenes.
Fugue-Very elegant and classical-ish. Could be a general 'love scene' song, or maybe associated with Katja's route.
Sacher and Karlsbader-A general school theme, or associated with a side character. I don't even have any real guesses for this one.
Shades of Echo-Possibly the 'comic scene' theme.
19th Century Girl-I don't know if any of the heroines could be described as a '19th Century Girl'. So possibly a side character. If it is a girl, maybe one of the Twins or Jeanne? The piece sounds rather tense, the drums imitating a clock add a lot of this tension I think. To me it suggests maybe anxiety, or compulsiveness. This one, and The Broken Mirror are the ones I'd most expect to be associated with characters.
My method for pairing songs with girl's routes was trying to decide what sort of mental disorder vibe I get from the piece and then pairing it with a girl based on what mental disorders I think that *they* have. So, this is doubly speculative, and almost certainly wildly incorrect. Still, what sort of predictions do you guys have?