The "AG RiffMaster" is a Guitar Hero/Rock Band controller for the Playstation 2, built into a real wooden-body guitar. (Not the first by any means, but the first commercially produced model.)
Sadly, IGN reviewed the RiffMaster and found it wanting, especially for a model that costs $400.
The weight and size of the instrument feels quite realistic, and if you're accustomed to playing a real electric guitar the similarity can be comforting. We noticed, however, that the distance between the frets and the strummer on the AG RiffMaster is actually shorter than typical plastic guitars. We consequently found ourselves naturally inclined to grip the RiffMaster higher on the neck than the buttons allow, and wondered if Art Guitars might consider shifting the fret button arrangement up the neck. Such a change probably wouldn't look as attractive as the current placement, however, so we can understand why Art Guitars chose the positioning it did.
A super-expensive guitar controller that doesn't perform its primary function very well? IGN gave it a for-them-damning 7.7 out of ten.
AG RiffMaster Guitar Hero Controller Review [Gear.IGN.com]