Pitch axis theory

Pitch axis is a really useful compositional tool for creating atmospheric and interesting chord sequences.

Don't be scared off by the name because pitch axis is a fairly simple concept. Joe Satriani and Steve Vai are two of the most famous guitarists to make use of this technique.

The basic idea is to choose a root note and move through two or more modes related by the root note. For example you could have a C Lydian chord vamp and then switch to a C Dorian vamp. The chord progression for this would look something like:

Cmaj7#11 | Cmaj7#11 | Cm7 | Cm7

As you can see we are changing scales but keeping the root note the same. Keeping a common rote note makes the modal changes more obvious.

The Joe Satriani track "Not of this earth" is a perfect example of this technique at work. The chord progression looks like this:

Emaj13 | Emin7 (b13) | Emaj13 | E7sus

The modes used to play over this progression are:

E Lydian | E Aeolian | E Lydian | E Mixolydian

Try using this technique in your own music and come up with your own progressions. You can move between major scale modes, melodic minor modes and harmonic minor modes to create some really amazing chord progressions.

Here is one more example of this technique

Emaj13 | E7b5 | Ema7#5 | Emin7

The modes used to play over this progression are:

E Lydian | E Lydian b5 | E Lydian #5 | E Dorian

Thats it for this lesson. Hopefully you can use these ideas in your own playing.