B♭ Mixolydian — 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)Bb(4)
Degree 2 · II(4)C(4)
Degree 3 · III(4)D(4)
Degree 4 · Degree 4E♭·A♭·D
Degree 5 · V(4)F(4)
Degree 6 · VI(4)G(4)
Degree 7 · Degree 7A♭·D·G