Rootless Voicing

The A♭BDG Voicing

The A♭BDG Voicing (the diminished-family box voicing) holds the shape A♭–B–D–G. Because the upper structure of a Dom7♭9 is itself a diminished 7th, the same four notes function as four dominants (G7, B♭7, D♭7, E7 — a minor-third cycle) and four diminished chords (A♭°7, B°7, D°7, F°7) with G as the added tension.

A♭BDGThe A♭BDG VoicingRootless
A♭3
B3
D4
G4

Bass clef

ModesDiminished Scale

8 Chord Interpretations

The upper structure of a Dom7♭9 chord is a diminished 7th. So one shape unlocks four dominants (a minor-third cycle: G7, B♭7, D♭7, E7) and four diminished chords (A♭°7, B°7, D°7, F°7 — with G acting as the added tension).

#ChordVoicing formula
Dominant 7♭9 family
1G7♭9♭9 · 3 · 5 · 1
2B♭7 13/9♭7 · ♭9 · 3 · 13
3D♭7♯11♭95 · ♭7 · ♭9 · ♯11
4E7♯93 · 5 · ♭7 · ♯9
Diminished 7th family (G as added tension)
5A♭°7 (add G)1 · ♭3 · ♭5 · (T)
6B°7 (add G)♭♭7 · 1 · ♭3 · (T)
7D°7 (add G)♭5 · ♭♭7 · 1 · (T)
8F°7 (add G)♭3 · ♭5 · ♭♭7 · (T)

Operating rule: Diminished Scale → Dom7♭9 (start on the ♭9) or Dim 7th (start on the root).

Want the full picture? The voicings hub shows all three voicings side by side, plus the master modes-to-voicings reference that tells you which shape to reach for in any harmonic situation.