How should i run Windows on my MBP w SSD? I only use "1" program with Windows...

try WINE to run a single windows program on OSX

Before you try the other solutions, why not try WINE (http://www.winehq.org/ ) -- it doesn't work for every windows program, but works for many, and is free. It does *not* require you to own a licensed copy of Windows, as the other two solutions you mention do.

If WINE doesn't work, then the question is whether you'll need to use the program for your guitar frequently, and use it while you're doing other stuff with your Mac, in which case I'd recommend Parallels. This is because Parallels runs as an application in OSX, meaning you can be running your other Mac software simultaneously.

On the other hand, if you use the program infrequently and in isolation, then Boot Camp should work for you. Each time you boot, boot camp allows you to choose either OSX or Windows and boots natively into that OS. To switch to the other, you have to reboot, which is obviously inconvenient (or even unworkable) if you do a lot of switching back and forth. One final consideration -- if the software is very resource intensive (like, for example, some games), then Boot Camp might work better.

 

Especially if you have a SSD, the amount of used disk space you use is probably a factor.

Using Boot Camp will require partitioning your drive. You'll essentially have to guess how much space Windows + your app will require. If you guess too much, you've essentially wasted disk space. It'll be sitting out there unused in the Windows partition, unavailable for use by your Mac.

If you use a VM (like Parallels or Fusion), instead of partitioning your drive, your Windows machine uses a "virtual disk", which is essentially a Mac OS file that grows as needed (up to the maximum size you told it). There's no wasted disk space with this method. Fusion even gives you the ability to shrink the file, should you add a bunch of stuff on Windows (which grows the file) and then remove a bunch of stuff. Parallels probably does too, but I'm not sure.

I agree w/ studycomp. See if WINE will work. But if it falls to Boot Camp or a VM, if disk space is a consideration (which it is for me, on my 256GB SSD), I'd really consider a VM.

 

Really the better question to ask is how demanding is this windows program going to be and let that decide how you run it.

I was in a similar situation as you but with a program called SolidWorks, this program is the only reason I boot into windows. I decided to use bootcamp to run windows and the program because of the large demand it places on the CPU and GPU, then there is the fact that most graphics intensive games run better when played in windows so it was safe to assume that running SolidWorks would run better in windows however they don't make SolidWorks for OS X so it a moot point really.

 

Such a program may not work in a virtual machine as it still goes through OSX to reach the device. It depends on how the application interacts with the hardware but more often than not you need to be running Windows natively (ie Bootcamp).

If I were in your position (and VM does not work) I would go on ebay or craigslist etc and find a really cheap Windows notebook to do the job or install Windows on an external drive to boot off of.