# Pitch Axis Theory

After a brief introduction to modes, I will explain The Pitch Axis Theory which isn't very well-known but quite fun to use. I came to it while learning to play some songs by my favourite guitarrist, Joe Satriani and if your level is intermediate-advanced, you might find it interesting. To end up the lesson, I'll show you an analysis of the song ''Not of this Earth'' from the same artist.

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Hello everyone! Firsly, thanks for reading, it's my first article in UG but I'll try to do it the best as possible. However, English isn't my mother tongue so please, pardon my inaccurate terminology. To begin with, modes were discovered in order to escape from diatonic restraint that didn't allow composers to use all 12 notes limiting it to 7 (number of notes that the mayor scale have). Modes are more abstract that what we imagine. Each of them have a special sound which is product of forcing another tonic in a scale. To follow on, I'll prove the characteristic of each mode. For doing this I'll use key of C mayor because it's much easier to see: -Like everyone should know, a mayor scale is built with the following drawing: T T 1/2 T T T 1/2* *T= tone , 1/2= semitone so the first modal scale* is: Ionian scale: C D E F G A B *Please, differ modes (speacial sound)with modal scale (the scale beggining from the other tonic) because I've seen it used wrongly in many lessons. -The second drawing is the following: T 1/2 T T T 1/2 T * *Notice that I've just began the earlier drawing with the second tone Dorian scale: C D Eb F G A Bb Dorian compared to a mayor scale = 1 2 b3 4 5 6 b7 -The third drawing it's: 1/2 T T T 1/2 T T Phrygian scale: C Db Eb F G Ab Bb Compared to the mayor scale it's = 1 b2 b3 4 5 b6 b7 -The fouth drawing is : T T T 1/2 T T 1/2 Lydian scale: C D E F# G A B Compared to the mayor Scale it's= 1 2 3 #4 5 6 7 - The fith drawing is: T T 1/2 T T 1/2 T Mixolydian scale: C D E F G A Bb Compared to the mayor Scale it's = 1 2 3 4 5 6 b7 - The Sixth drawing is: T 1/2 T T 1/2 T T (minor scale) Aeolian scale*: C D Eb F G Ab Bb Compared to the mayor scale it's: 1 2 b3 4 5 b6 b7 *After finishing this, I'll compare dorian and phrygian scale to the aelian scale (minor scale) - Finally the sixth drawing is: 1/2 T T 1/2 T T T Locrian Scale: D Db Eb F Gb Ab Bb ______________________________________________________________________ To sum up: Lydian= mayor scale + #4th Mixolydian= mayor scale + b7 Dorian= minor scale + Mayor 6th Phrygian= Minor scale + b2 ________________________________________________________________________ -The Pitch Axis Theory: It involves fixing the main tonality and change modes on that fixed axis. Example: ''fixed tonality C''
``` Cmay7#11  /   Cm6   /    C7    /   Csus4/may7 *

C Lydian  / C dorian/ C Mixolydian / C Ionian```
* Notice that I'm using restrictive chords; in other words, I'm using chords that only allow one mode. The most commun are:
```- _may7#11 -  1 3 5 7 11#(4#) - Only Lydian scale has that 4#
- _m6      -  1 b3 5 6        - Only Dorian has b3 and mayor 6th
- _dom(7,9,13...)- 1 3 5 b7 * -Only mixolydian has 3 and b7
*(might have other tensions)```
*Sometimes what you want is the opposite: With one chord use several modes. In order to do this, the best option are suspended chords: - _sus4 - Over this chords you might use Ionian, Dorian, Mixolydian, Aelian and phrygian scales. - _sus2 - Over this chord you might use Ionian, Dorian, Lydian, Mixolydian, Aeolian ______________________________________________________________________ Not Of This Earth The Fixed tonality in this song is E but the chords don't have E in the bass It begins with a calm, intriguing intro which chords are: C#m add9 / Cadd9 / C#add9 / Asus4 * *The beginning of this analysis has been made by myself. You won't find it like this in any webpage... But there is not fixed tonality so what Satriani does is to invert those chords with the base note E * *Note: The low E is done with the base guitar in the song So the chords finally look like: Emay7/6 / Em7/ b6 (no 5) / Emay/6 / E7sus4 First chord- With this chord you could use lydian and Ionian. Satriani choose's Lydian (better option because of it's sound) Second Chord- You could use Phrygian and Aeolian. Satriani chooses Aeolian Fourth Chord- You can only use E mixolydian. The result is the following: Elydian / E Aeolian/ E lydian / E Mixolydian Before ending up the lesson I must do some publicity to Joe Satriani: He's way of playing has inspired me to learn to play the frets but his knowledge is well beyond from what we've seen today, he can play any type of music but instead, he shows his own style where he expresses what he feels with notes. Apart from publicity, I tell you that all this can get really complicated. Today, we have only used mayor scales... Out there, people are using modes theory with harmonic and melodic minor... Besides, there are many exotic scale waiting to you to find them. I encourage people to learn music because it's what makes me who I am. Well, finally the lesson is over, I hope it's been useful. My intention is to upload more but first, I'll see how it goes. Thank you again for reading! Lesson by: B.P.J from Seville, Spain

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