I have had a copy of this book for probably three or four years. I've played guitar for about eight years, and this is one of the best tools I've ever used. I've used it, and used it, and am on here to look at getting another copy because mine is falling apart from the constant use. This may just seem like a book of scales, but knowing these scales and how they works help you with playing and performing greater than you think it would. I have improvd vastly from this book, and I imagine most others would as well. I would recommend to the beginner and expert alike.