Some time ago I read "On Intelligence" by Jeff Hawkins. In this book he presents his hypothesis that the human intelligence is based mainly on prediction, to put it in a nutshell. Building on this I developed an explanation approach for the question why we enjoy music.
The whole is based on the observation that you get adapted to music with time. Maybe you really dislike a music style the first time you are listening to it. But the more often you listen to this music, the more you will like it. If listen long enough to this music style you may really get to like it.
I assume that the brain tries to predict possible tone sequences of the heard music in every moment. If these predictions match the reality this will result in a feeling of success which results in the feeling that you like the music. But if a music style is unknown to your brain, than it predictions will be often wrong. If you would start listening this particular style more often, your brain will learn the patterns of that music style like typical tone sequences or rhythms. Therefore, the number of correct predictions will increase and you will like the music style more.
Of course this cannot explain all music preferences. There is probably a lot of other important factors. I do not even have any scientific proofs. Anyhow, it is a basic idea which maybe can be used for further work.
By the way, it also happens that you listen so often to some kind of music like a little bit until you cannot hear it anymore and you really dislike that music. In this case, maybe, is missing the new and your brain is bored. Particularly, it was discovered as far as I know that new experiences let the brain release "happiness hormones". Because music is not new anymore after listening to it very often, this would contradict the effect described above (if it really occurs).