Virtually all available blues harmonica books and materials are *way* too overly simplistic. And the title and lame cover illustration of this book led me to believe that this was just another generic book showing me how to achieve a single note, bend, play some beginner tunes, introduce the I, IV,V, etc.
But this turned out to be exactly what I've been looking for. This book has the information on performing blues I've seen nowhere else:
* which degrees of each scale are blues chord-tones (1, 3, 5, and sometimes others) and non-chord tones
* the eight ways in which non-chords can be used in a blues riff (passing tone, neighboring tone, appoggiatura, etc).
* what the chord line of the tune is (not just the melody)
* how to improvise over the "chord of the moment."
* how to not get lost while improvising
This is the "meat" every harmonica player *must* eventually get to if you seriously want to play real dynamic blues. It's also one of the not-so-fun elements of the harp if you're coming from a non-musical background. Glenn admits that the harmonica is a poor vehicle to learn theory on because of it's design. But he does a wonderful job of demistifying all of it.
I'm sure this is the next step for countless harp players out there that have the technique down but just don't know how to get up there and blow some real mesmerizing blues.