ARS: Rock Band 3 wants to teach you how to play music, or at least get you started down that road. We explained the Pro mode with the keyboard peripheral in our review of the game and now we're back with our thoughts on the Pro Guitar mode. Bottom line: the $150 Mustang peripheral is expensive, and a fretboard covered in buttons may seem intimidating, but it's worth the time and investment.
Rock Band 3 may not be able to teach you guitar if you've never picked up an instrument, but added to lessons from a real-world teacher, it becomes a powerful practice tool. For those of us who already play, it works as a fun way to improve fundamentals.