Modal Progression

Modal Progressions consist of chords created exclusively from one mode. Like any chord progression, the chord sequences must produce resolution to the I chord of the key. In order to characterize the particular mode, the predominant secondary chords must contain the unique notes of the mode.

**Unique Notes**
examples in key of C
Mode ----- Formula	Unique Note(s) ----- Scale Degree	Secondary Chord(s) ----- Rom. Num. Analysis
Lydian
1 - 2 - 3 - #4 - 5 - 6 - 7 - 8/1	#4	D⁷, F#^-7b5, Bm⁷ ----- II⁷, #IV^-7b5, VIIm⁷
Ionian
1 - 2 - 3 - 4 - 5 - 6 - 7 - 8/1	4, 7	Dm⁷, F^maj7, G⁷ ----- IIm⁷, IV^maj7, V⁷
Mixolydian
1 - 2 - 3 - 4 - 5 - 6 - b7 - 8/1	b7	Bb^maj7, Gm⁷ ----- bVII^maj7, Vm⁷
Dorian
1 - 2 - b3 - 4 - 5 - 6 - b7 - 8/1	6	Dm⁷, F⁷ ----- IIm⁷, IV⁷
Aeolian
1 - 2 - b3 - 4 - 5 - b6 - b7 - 8/1	2, b6	Bb⁷, Gm⁷, Ab^maj7, Fm⁷ ----- bVII⁷, Vm⁷, bVI^maj7, IVm⁷
Phrygian
1 - b2 - b3 - 4 - 5 - b6 - b7 - 8/1	b2	Db^maj7 ----- bII^maj7
Locrian
1 - b2 - b3 - 4 - b5 - b6 - b7 - 8/1	b5	Gb^maj7 ----- bV^maj7

Modal harmony is exclusive, meaning only scale tones are used to construct the chords of the harmonic progressions. Excepting the Ionian mode, which produces harmony equivalent to diatonic harmony, modal progressions lack a primary dominant chord. This lack of cycle of fifths dominant-to-tonic resolution increases the risk of harmonic drift, which occurs when a series of chords produces resolution to the tonic of the parent scale instead of the mode's I chord. This means most modal progressions use two or three chords in a repeating vamp, using repetition to reinforce the tonal center.

**Modal Chord Groups**
Mode	Main Chords	Example in Key of C
Ionian	I, IIm⁷, V⁷ I, IV, V⁷	C, Dm⁷, G⁷ C, F, G⁷
Mixolydian	I, bVII	C, Bb
Dorian	Im⁷, IIm⁷ Im⁷, IV⁷	Cm⁷, Dm⁷ Cm⁷, F⁷
Aeolian	Im⁷, IVm⁷, Vm⁷ Im⁷, bVII, bVI	Cm⁷, Fm⁷, Gm⁷ Cm⁷, Bb, Ab
Phryian	Im⁷, bII^maj7	Cm⁷, Db^maj7

The addition of less modally-defined chords occurs, often with less frequency or duration. The IV chord is often added to a Mixolydian progression, and the bIII chord is added to Phrygian progressions. These chords do not define the mode, but introduce some additional harmonic motion.

Lydian and Locrian do not produce harmonic progression, as the I chords in these modes don't produce a feeling of resolution using secondary chords containing unique notes from the mode.