Yes, assuming that you have room on your hard drive, getting Windows running on a Mac is as easy as:
1. Buying a copy of Windows 7/64($199 from Best Buy
http://www.bestbuy.com/site/Windows+7+Ho...;lp=7&cp=1)2. Run Bootcamp on your Mac, you will divide your hard drive between Mac and Windows, and install Windows 7/64.
You're done, and then you can run the Windows or Mac version of Band-in-a-Box.
For someone who already has the Windows version of Band-in-a-Box, this option might actually be cheaper, since you don't have to buy Band-in-a-Box again.