there are really alot of sub-fields, and I was faced with the same question before I chose audio engineering.
other things I thought about were classical / jazz muzik, sonology, electronic production, electronics..
since myspace doesn't work on my pc I couldn't listen to your music,
so the best I could say is ask yourself what is a subject you are good at but still find challenging,
where you feel you have good ideas on how to do it better than what you hear,
and maybe most important in this context, what do you feel that you can learn alone, and what you need someone to make some sense for you.

also, it's not a crime to study a some of this and some of that,
but talk to people to make sure the first year of a course is also worth something.

oh and good luck