You should note that there is a very practical use for a sense of beauty. Not only for mate selection, which has been mentioned, but for determining where to live and if a place is safe. For instance, if you see a whole lot of nothing, as in a desert, you might think that it is very inhospitable to life (human life, at least). Or maybe you see bones or blood, which you would find repulsive, and think to yourself, "Hey, maybe I'm about to be eaten." Whereas the colors of plants, flowers, trees, and water would remind you on the subconcious level that there is water, food, and some sort of shelter nearby, even if you didn't have the ability to figure this out rationally.

As for romantic love, there is a lot of evidence that chemicals called "pheremones" help determine if you are attracted to someone. I don't know much about the subject, but I think of this as being done unconciously, in that we sense these pheremones that generate some funny reaction in us involving sex hormones and adrenelin.

A lot of us have concious or unconcious desire to prove ourselves better than others. This would be analogous to a prehistorical social heirarchy, kinda like what we hear about the social structure of animals that travel in packs like dogs (wolves), cats (lions and tigers), and Windows users.

Updated: Oh right, and about that music thing. Ever notice how children can sleep better when there's soothing music in the background (ie. a mother singing or something cliché like that)? My theory is that there are certain sounds we are "trained" to enjoy: the voices of our family, the sound of rushing water, or something. Apprecation of modern music tends to be a learned trait, rather than something inherent in a person, but I think it developed from this. Also, ever have an experience where a song reminds you of where you were the last time you heard it? That happens to me with the themes of movies, too, but the weirdest thing is that there are certain songs that make me feel like it's a completely different season. That seems to be how our memory works.