For a while now, there have been some folks asking in various forums about some of the theory behind the examples in Jazz Guitar Technique. Since the book is about how to get your hands to do certain things relating to playing the guitar, it isn't really the place to talk about theory. This Web page IS the place to talk about it.

This will work really well if you ask about an example that you would like explained.

G7 Altered Scale is the 7th mode of the Ab-Maj7 scale. This is actually the easiest way to remember the Altered Scale. Use the Minor Maj7 scale a half step above the root of the altered dominant chord. The altered scale is the linear version of a Dominant chord with b9, #9, #4, b13, with no fifth.

That the line starts on beat three of the D-7b5 chord illustrates an important point about the way the great improvisors in Jazz create phrases. When people are learning to improvise, and gain knowledge of scales and arpeggios, there is a strong tendency to play each measure as if it had a wall around it. Measure A is the Locrian Mode; Measure B is the Altered Scale; Measure C is the Ionian Mode. If you transcribe the great improvisors (a great thing to do), you will quickly realize that they phrase across the barlines frequently. The above example is actually a mild case of over-the-barline phrasing.

This device creates a sense of excitement when you hear the momentary use of "wrong" notes against a chord. In the above example, there are notes heard against the D-7b5 chord that are not technically correct. Cb and Db for example. Rather than hear these notes as "wrong", the ear interprets the sound of the ascending scale from root to fifth on the downbeat of the G7 measure as a logical musical structure.