A few years back my son and I were in GC checking out various method books, and he'd settled on a very expensive (and thick) book - can't remember what it was. At the register, one of the (few) staff who really knew their stuff, recommended my kid save his money and get the skinny version of the Guitar Grimoire - great advice. It's improved my overall knowledge and improvising (and I'm a keyboardist!), and my son's never looked back - aced AP theory his senior year, and he's now a music minor in college. Just phenomenal book including "non Western" modes I'd never heard of.
