I strongly recommend getting a Mac over a PC.
I make my living with music and use both a Mac and a PC. I only use the PC to run GIGA Studio, but have imported most of the best GIGA sounds into the EXS-24 for Logic (Mac) to avoid the PC as much as possible. I find the PC much more cumbersome and more likely to crash than the Mac. I have 2 kids in music. They each use Macs. (One of them is at Oberlin where it must be 10 to 1 in favor of Macs.) Almost every professional musician, composer, engineer, etc. I work with uses Macs. They are much more reliable than PCs and are not as susceptible to viruses. Even programs that have both PC and Mac versions run better on the Mac, especially Pro Tools, which is the industry standard for recording and editing music. The great majority of music schools use Macs.
That being said, although almost every music professional I know uses Macs, I work with an extremely successful, world-class musician who has always used a PC. Several young (25-35) musicians use PCs because Macs used to be so much more expensive, so when they went to college they bought PCs. It's just, having used both for music, my humble opinion that the Mac is the better choice, and very competitive price-wise, especially with iLife, iSight, and all the other programs and features standard with the Mac operating system. Also, don't forget that ever since the Mac switched to Intel processors, it can run Windows and all of the PC programs. So, you can have your cake and eat it, too.
One last comment. No matter which system you choose, for college you should get a laptop. Here is a good explanation of why Mac laptops have become so popular lately:
Macworld | The new rules for buying a Mac