This book provides the basic structure that you can fill in with the subsequent volumes of the series. Part two begins a deep dive into position playing and expands on part 1. I am just digging into volume 3 now, (via the all-in-one edition,) and it seems that by the time you’re done with volume 3, you are in outer space and ready to tackle anything. You achieve all 12 major keys in one six-fret block, and can play each key all along the fretboard. I like how by the end, the student has mastered any small section of the fretboard, and the fretboard as a whole. I unfortunately never met Leavitt, but I did study with one of his students at Berklee back in the day. He was a highly respected player, author and teacher who dedicated his life to making some sense of the zany guitar.