Dual Triads and Quartal Chords: Quartal Chords in Octatonic Scales
In the halftone wholetone scale, you can a build quartal chords from the b9, stacking a perfect fourth and an augmented fourth. You can combine two of these quartal chords a minor third from each other. The table shows the resulting notes in the key of C. Again, because of the symmetry of octatonic scales this structure can be moved up and down minor thirds at will.
|Db Gb C + E A Eb
|C Db Eb E Gb A