Watch the V7b9 online guitar lesson by Brad Carlton from Guitar Lab: ii V I Options
This lesson explains the theory behind a V7b9 chord. This chord is made up of the following tones: root, third, fifth, flat seven, and flat nine. If you separate the root of this chord, you will see the remaining four tones form a diminished seventh chord. This is quite useful because of the way that a diminished seventh chord inverts every three frets. Diagrams 100 through 103 apply to this lesson.