Modes

Modes are basically repurposed uses of existing scales by altering which note is used as the tonic. The most common mode is the Aeolian, which uses the 6th note of the major scale as its root. As we've already studied, this is the natural minor scale.

Disambiguation with Historical Connotations

Historically in music, the term mode (modus in Latin) was used to refer to various common practices in music, such as common rhythms, etc. See wikipedia for more information. We are only focused on the repurposed scales. Historically, there have been 3 separate times and locations where this has occurred. One is the Greeks, and one is the medieval churches in the West. We are not concerned with these, as their basic foundation of music theory and scales tend to differ from the ones we have learned. That leaves us with the "Modern" conception/usage of modes.

Common Modes

Given the standard 7-note Major scale, we can start/end melodic phrases on any of the particular notes, treating them as the tonic. These are named the following:

Mode Name	Tonic's Location in Maj. Scale	whole/half pattern	Uni	m2	M2	m3	M3	P4	d5	P5	m6	M6	D7	M7	Oct
Ionian	I	w-w-h-w-w-w-h	x		x		x	x		x		x		x	x
Dorian	II	w-h-w-w-w-h-w	x		x	x		x		x		x	x		x
Phrygian	III	h-w-w-w-h-w-w	x	x		x		x		x	x		x		x
Lydian	IV	w-w-w-h-w-w-h	x		x		x		x	x		x		x	x
Mixolydian	V	w-w-h-w-w-h-w	x		x		x	x		x		x	x		x
Aeolian	VI	w-h-w-w-h-w-w	x		x	x		x		x	x		x		x
Locrian	VII	h-w-w-h-w-w-w	x	x		x		x	x		x		x		x

So if we used the scale of notes from the key of C Major, the Ionian mode uses C as the tonic. C Ionian is the same as our normal C Major key. Aeolian uses A as the tonic, which is the same as A natural minor. The others we are less familiar with. But starting on D would be Dorian, E Phrygian, F Lydian, G Mixolydian, and B Locrian.

Notice how as the modes progress from I to VII, the whole-half patterns and interval chart seems to move diagonally from top right to bottom left. Yet if you simply look at the interval chart from line to line, the changes seem fairly random. Once they are arranged in fifths, however, they become more ordered.

Here's some more tables for reference to wrap your head around this.

Same table but arranged in fifths

Mode Name	Tonic's Location in Maj. Scale	whole/half pattern	Uni	m2	M2	m3	M3	P4	d5	P5	m6	M6	D7	M7	Oct
Lydian	IV	w-w-w-h-w-w-h	x		x		x		x	x		x		x	x
Ionian	I	w-w-h-w-w-w-h	x		x		x	x		x		x		x	x
Mixolydian	V	w-w-h-w-w-h-w	x		x		x	x		x		x	x		x
Dorian	II	w-h-w-w-w-h-w	x		x	x		x		x		x	x		x
Aeolian	VI	w-h-w-w-h-w-w	x		x	x		x		x	x		x		x
Phrygian	III	h-w-w-w-h-w-w	x	x		x		x		x	x		x		x
Locrian	VII	h-w-w-h-w-w-w	x	x		x		x	x		x		x		x

Tonic's Location in Maj. Scale	Mode Name	whole/half pattern	2nd	3rd	4th	5th	6th	7th
Ionian	I	w-w-h-w-w-w-h
Dorian	II	w-h-w-w-w-h-w		b				b
Phrygian	III	h-w-w-w-h-w-w	b	b			b	b
Lydian	IV	w-w-w-h-w-w-h			#
Mixolydian	V	w-w-h-w-w-h-w						b
Aeolian	VI	w-h-w-w-h-w-w		b			b	b
Locrian	VII	h-w-w-h-w-w-w	b	b		b	b	b

Same table but arranged in fifths

Tonic's Location in Maj. Scale	Mode Name	whole/half pattern	2nd	3rd	4th	5th	6th	7th
Lydian	IV	w-w-w-h-w-w-h			#
Ionian	I	w-w-h-w-w-w-h
Mixolydian	V	w-w-h-w-w-h-w						b
Dorian	II	w-h-w-w-w-h-w		b				b
Aeolian	VI	w-h-w-w-h-w-w		b			b	b
Phrygian	III	h-w-w-w-h-w-w	b	b			b	b
Locrian	VII	h-w-w-h-w-w-w	b	b		b	b	b

	Ionian	Dorian	Phrygian	Lydian	Mixolydian	Aeolian	Locrian
E-A-D or A-D-G patterns	|-|o|x|-|-| |o|-|o|-|o| |x|-|o|-|o|	|o|-|x|-|-| |o|-|o|-|o| |x|-|o|o|-|	|o|-|x|-|-| |o|-|o|o|-| |x|o|-|o|-|	|-|o|x|-|-| |-|o|o|-|o| |x|-|o|-|o|	|o|-|x|-|-| |o|-|o|-|o| |x|-|o|-|o|	|o|-|x|-|-| |o|-|o|o|-| |x|-|o|o|-|	|o|-|x|-|-| |o|o|-|o|-| |x|o|-|o|-|
w/ Flats and Sharps rel. to Major	|-|o|x|-|-| |o|-|o|-|o| |x|-|o|-|o|	|b|-|x|-|-| |o|-|o|-|o| |x|-|o|b|-|	|b|-|x|-|-| |o|-|o|b|-| |x|b|-|b|-|	|-|o|x|-|-| |-|#|o|-|o| |x|-|o|-|o|	|b|-|x|-|-| |o|-|o|-|o| |x|-|o|-|o|	|b|-|x|-|-| |o|-|o|b|-| |x|-|o|b|-|	|b|-|x|-|-| |o|b|-|b|-| |x|b|-|b|-|
Open Position Using C Maj. Scale	o|o|-|o| o|x|-|o| o|-|o|-| o|-|o|o| o|-|o|x| o|o|-|o|	o|o|-|o| o|o|-|x| o|-|o|-| x|-|o|o| o|-|o|o| o|o|-|o|	x|o|-|o| o|o|-|o| o|-|o|-| o|-|x|o| o|-|o|o| x|o|-|o|	o|x|-|o| o|o|-|o| o|-|o|-| o|-|o|x| o|-|o|o| o|x|-|o|	o|o|-|x| o|o|-|o| x|-|o|-| o|-|o|o| o|-|o|o| o|o|-|x|	o|o|-|o| o|o|-|o| o|-|x|-| o|-|o|o| x|-|o|o| o|o|-|o|	o|o|-|o| x|o|-|o| o|-|o|-| o|-|o|o| o|-|x|o| o|o|-|o|
Open Position w/ C as Root	o|o|-|o|-| o|x|-|o|-| o|-|o|-|-| o|-|o|o|-| o|-|o|x|-| o|o|-|o|-|	||o|-|o|-| ||x|-|o|o| o|-|o|o|-| o|o|-|o|-| o|o|-|x|-| ||o|-|o|-|	||o|-|o|o| ||x|o|-|o| o|o|-|o|-| ||o|-|o|-| ||o|-|x|o| ||o|-|o|o|	o|-|o|o|-| o|x|-|o|-| o|-|o|-|-| o|-|o|-|o| o|-|o|x|-| o|-|o|o|-|	o|o|-|o|-| ||x|-|o|-| o|-|o|o|-| o|-|o|o|-| o|o|-|x|-| o|o|-|o|-|	||o|-|o|o| ||x|-|o|o| o|-|o|o|-| o|o|-|o|-| ||o|-|x|-| ||o|-|o|o|	||o|o|-|o| ||x|o|-|o| ||o|-|o|-| ||o|-|o|o| ||o|-|x|o| ||o|o|-|o|

Pitch Axis Theory

Pitch Axis is a method of composition that tends to retain a common root note across a chord progression, simply changing the quality and embellishments of the chord. A sample sequence could be A, Am, A°, A+. No single scale contains all these chords. Instead, one could use the A Ionian, Lydian, or Mixolydian over A. Then A Dorian, Phrygian, or Aeolian over Am. Then A Lydian or Locrian over A°. And finally A Harmonic Major, Augmented, or Whole Tone over A+.

This approach really emphasizes the changes in how the root note is approached and how it interacts with the other notes. It can feel almost like a random modulation, but the common root note ties it together and makes for quite adventurous progressions and melodies.