I need some software to create simple back tracks of basic rock, metal and blues tracks. Band in a Box for PC looks like a good solution. I can't locate a demo version and have never used such software. Does the program come with any sound loops I'd need, or do I have to buy that separately? I'm not looking for anything fancy, just some basic background for students to try their fingers at soloing. I'm talking about the version that lists for about $130.