F♭ Dorian — Quartal voicings
Three-note stacks of fourths, one per scale degree — the open, ambiguous voicing-flavour McCoy Tyner and Bill Evans built modal-era jazz around (the 'So What' chord).
All 7 quartal voicings in sequence
Degree 1 · I(4)Fb(4)
Degree 2 · II(4)Gb(4)
Degree 3 · Degree 3A𝄫·D♭·G♭
Degree 4 · IV(4)Bbb(4)
Degree 5 · V(4)Cb(4)
Degree 6 · VI(4)Db(4)
Degree 7 · Degree 7E𝄫·A𝄫·D♭