Why the music?

Amelia blogged some interesting thoughts on music. And so I am going to throw out something that I have always wondered. Why do we like the music that we like? I have such a different variety from Metallica to Country to Mozart in my CD collection. What are the possibilities for liking the music we like? Do we like the music we like because: we are conditioned to like the music through association of events or emotions? Certain songs remind us of an event or emotion that we want to relive or feel again? Is it anatomical and the certain meter and rhythmns of songs come together to vibrate the cochlea in the inner ear just at the right frequency? Is the type of music learned from the parents or some other way, Nature or Nurture? Is there really any pattern or is it just random in the way we like music? It would be interesting to hear of everyone's thoughts..........