Milton's Modal Compass

Awareness of modal scales is essential for overtone singers!

Milton Mermikides is a very talented musician and he is equipped with a deep sense and understanding of the inherent structures of music. I became aware of him as an ally in my mission to debunk 432 Hz superstition, which he has written an excellent article on. From his outline I have designed this diagram showing the inherent dynamics of modal scales (based on church modes ), which may occur if you limit yourself to the white keys of the piano (notes without accidentals), but the modes may be played with any of the 12 keys as a fundamental, so it is more correct to consider them as patterns of minor (semitones) and Major (whole tone) steps.

The seven ( modern, Western ) modes:
A, Aeolian: Major-minor-Major-Major-minor-Major-Major
B, Locrian mode: minor-Major-Major-minor-Major-Major-Major
C, Ionian: Major-Major-minor-Major-Major-Major-minor
D, Dorian: Major-minor-Major-Major-Major-minor-Major
E, Phrygian: minor-Major-Major-Major-minor-Major-Major
F, Lydian: Major-Major-Major-minor-Major-Major-minor
G, Mixolydian: Major-Major-minor-Major-Major-minor-Major

The structure of heptatonal scales. The seven modes is a subset of this general pattern. Locrian mode is the exception as it includes diminished fifth.

- D (Dorian mode) has been chosen as the starting point, because its is symmetrical: Whether you ascend from Prime to Octave or descend from Octave to Prime it follows the same sequence of Major and minor steps.

- Across the central vertical axis three modal pairs are mutual inversions (light blue, dotted lines): A-G (Aeolian-Mixolydian); E-C (Phrygian-Ionian) and B-F (Locrian-Lydian).
First example, A-G: Major-minor-Major-Major-minor-Major-Major is mirrored by the Major-Major-minor-Major-Major-minor-Major.

- The modes of the right side of the diagram (Mixolydian, Ionian and Lydian mode) are characterized by Major (sharp/bright) interval functions, whereas the modes of the left side (Aeolian, Phrygian and Locrian mode) are characterized by minor interval functions.

- Moving clockwise the modes turn sharper (brighter), whereas the modes become flatter (darker by counterclockwise motion.

- The dark blue circles indicate the steps which are modified by movement between neighbouring modes in the circle, for example, the Third of  D-G: By the progression from Dorian to Mixolydian mode all notes remain identical except for the Third, which is raised one semitone from minor to Major. If you move in the opposite direction, from Mixolydian to Dorian, the Major third becomes minor.

- Finally, the dark blue lines form a heptagonal star. It connects the neighboring degrees (A-B-C-D-E-F-G)

... In other words: A diagram packed with meaning! I'm just a little bit jealous that it was not me who conceived it, but I am very happy that Milton gave his approval to my further developments of the diagram!

In this representation at each stage the modal scales are indicated by circles, where the division in minor and Major step pattern becomes more visual. The fundamental of each scale is situated in the 12 o'clock position.
Modal pairs connected by dotted lines are mutual inversions.
The color code indicates the tendency to contraction (blue) and expansion (yellow-orange). Generally, minor and diminished intervals and chords have a contractionary effect, while Major and Augmented intervals and chords have an expansionary effect.
Nomenclature: m2 = minor Second; M2 = Major Second; m3 = minor third; M3 = Major Third; P4 = Perfect Fourth; A4 = Augmented Fourth; d5 = diminished Fifth; P5 = Perfect Fifth, m6 = minor Sixth; M6 = Major Sixth; m7 = minor Seventh; M7 = Major Seventh.