Dual Triads and Quartal Chords: Quartal Chords in Ionian, Melodic Minor and Harmonic Minor

In ionian, melodic minor and harmonic minor scales, two quartal chords a third from each other will result in the same kind of six note scales as above.

Quartal ChordsScaleCorresponding Triads
1-4-7 + 3-6-91-2-3-4-6-76-1-3 + 7-2-4
2-5-1 + 4-7-31-2-3-4-5-77-2-4 + 1-3-5
3-6-9 + 5-1-41-2-3-4-5-61-3-5 + 2-4-6
4-7-3 + 6-9-52-3-4-5-6-72-4-6 + 3-5-7
5-1-4 + 7-3-61-3-4-5-6-73-5-7 + 4-6-1
6-9-5 + 1-4-71-2-4-5-6-74-6-1 + 5-7-2
7-3-6 + 2-5-11-2-3-5-6-75-7-2 + 6-1-3

Two quartal voicings a second from each other will result in pentatonic scales.

Quartal ChordsScale
1-4-7 + 2-5-11-2-4-5-7
2-5-1 + 3-6-91-2-3-5-6
3-6-9 + 4-7-32-3-4-6-7
4-7-3 + 5-1-41-3-4-5-7
5-1-4 + 6-9-51-2-4-5-6
6-9-5 + 7-3-62-3-5-6-7
7-3-6 + 1-4-71-3-4-6-7

Again, not every combination works well in every situation.

When playing a quartal chord from the 4 or 7 in melodic minor, you will get a diminished triad. When building a quartal chord on the 4 in harmonic minor, you also get a diminished triad, but when starting on the 7, you will get a minor triad.