The Guitarist's Music Theory Book by Peter Vogl is the first music theory book designed for guitar by a guitarist. The book explains music theory as it applies to the guitar and covers intervals, scales, chords, chord progressions, and the Nashville Number System. You will also get online access to audio examples of all the music in the book and also an ear training section. The Music Theory Book was written to help all guitar players achieve a better understanding of the guitar and of the music they play.