Stop here if you're looking for an in depth book covering quartal harmony specifcally applied to the guitar. This is the best book I've seen so far on the subject. I've collected a few other books that don't nearly cover as much as this book does. Plenty of examples are provided and just the right amount of theory is explained. The author focuses more on getting you to integrate these quartal chord shapes into your playing. All the quartal chord voicings are covered and displayed across all the string sets. Examples and analysis for using each quartal voicing are provided as well. Different functions for the chords are provided. Using them in II V I progressions as well as using them in a modal fashion. At the end of the book are example showing how to use these voicings over a minor blues and a few jazz standards. It's surprising to me that this book isn't more popular. I wish I had got this book first beofre a couple others that only cover small portions of the subject. It's all here as far as I'm concerned.