Pitch axis theory
Pitch axis theory is a musical technique used in constructing chord progressions. The tonic, or root, is used as the base note, and melodic scales are chosen according to the chords that lie beneath them.
"Pitch Axis Theory" is a compositional technique that Joe Satriani has uses in a number of his songs, along with other guitarists such as John Petrucci, Steve Vai, Marty Friedman, Michael Angelo Batio and Guthrie Govan.
Contents |
Concept
The seven modes are all connected to each other by diatonic shifts: C Ionian (C-D-E-F-G-A-B-C) is also D Dorian (D-E-F-G-A-B-C-D), E Phrygian (E-F-G-A-B-C-D-E) and so on, until you return to the original C Ionian Mode.
Pitch axis theory suggests that for each mode, there is are chords that accompany it. When these certain chords occur, it implies a change between modes.
The table shows this link between chords and modes.
Examples
Here are some songs which use pitch axis theory, and how pitch axis theory works in them.
Not Of This Earth - Joe Satriani
This picture is the chord sequence and first melody of Joe Satriani's song "Not Of This Earth".
All the chords are based around the root note of E. This is the whole point of pitch axis theory, to keep the same tonic center whilst changing the mode.
The first chord has root note E and a major third (G#) so it implies a major mode. The mode which fits in with this, because of the C# isn't the Lydian, but a Lydian is played for the first bar of the four bar sequence, even though it technically shouldn't.
The second chord has the notes E, G, C, D. The G implies a minor mode, and as it contains the 7th, the aeolian mode is played in this bar.
The third chord has the notes E, G#, C#, D#. The G# implies a major mode and the D# implies the Lydian to be played again.
The final chord has the notes E, A, D. This is a Dominant 7th chord and implies the Mixolydian mode.
This 4 bar pattern of chords and Lydian - Aeolian - Lydian - Mixolydian continues throughout the entire song.
The Chords
As you can see the chords are not always simply the chords in the table. They use other notes to make them more interesting but still imply the same mode. Also you do not have to strictly stick to the table, because as Joe Satriani has said, "As long as you keep the tonal center the same, then you're doing the pitch axis trick".
Using Pitch Axis Theory
A g
Fourth Headline
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Related GMC Lessons
(this is a speical headline that is optional)
See also
(this is a speical headline that is optional)
