Voicing Box III · M3 + M2 + P4

Box III

Box I rotated again — the major third is now on the bottom and the perfect fourth on top. The chord interpretations are identical to Box I and II; only the bass voice (and therefore the colour) changes.

Voicing Boxes Series

Overview·Box I·Box II·Box III·Box IV·Box V·ii-V-I (I)·ii-V-I (II)

What this box is

Box III is a four-note rootless shape. Its interval signature from the bottom up is M3 + M2 + P4 (4 + 2 + 5 semitones). The shape itself doesn't change — only the chord you imagine underneath does. That's how a single fingering can voice 6 distinct chord qualities.

Six chord qualities

Each cell of Box III maps to these six qualities:

m77sus7♯9Δ♯5m7♭56/9

Cells

tap a cell to inspect its shape

Voicing

F – A – B – E

Stack from low to high — M3 + M2 + P4

Six chord interpretations of this shape

Dm7

7sus

G7sus

7♯9

D♯7♯9

Δ♯5

AΔ♯5

m7♭5

Em7♭5

6/9

F6/9

All six cells

Cell	Voicing	m7	7sus	7♯9	Δ♯5	m7♭5	6/9
1	F–A–B–E	Dm7	G7sus	D♯7♯9	AΔ♯5	Em7♭5	F6/9
2	A–D–E♭–A♭	G♭m7	C♭7sus	G7♯9	D♭Δ♯5	A♭m7♭5	A6/9
3	D♭–F–G–C	B♭m7	E♭7sus	B7♯9	F♯Δ♯5	Cm7♭5	D♭6/9
4	G♭–B♭–C–F	E♭m7	A♭7sus	E7♯9	BΔ♯5	Fm7♭5	G♭6/9
5	B–E♭–F–B♭	A♭m7	D♭7sus	A7♯9	EΔ♯5	B♭m7♭5	B6/9
6	E♭–G–A–D	Cm7	F7sus	C♯7♯9	GΔ♯5	Dm7♭5	E♭6/9

How to practise

Play one cell with both hands together — left hand finds the implied root, right hand plays the four notes.
Keep the right-hand shape and rotate the bass through all six chord interpretations. Notice how dramatically the colour changes.
Move up a perfect fourth to the next cell. The shape contour stays identical; only the keys change.
String two cells together as a ii-V — the boxes are designed to voice-lead by step.

Frequently asked

Why no root?

Two reasons. First, in a band the bass player has the root covered. Second, leaving out the root makes the upper structure shape work for many chords at once — that is the whole point of the system.

Are these chord shapes fixed?

The pitch-class set is fixed. The exact octave you place each note in is up to you and the voice-leading context. Most pianists keep the shape inside one octave to start, then spread it once it's under their fingers.

How does Box III relate to the other boxes?

Box I, II, III, and IV are four rotations of the same pitch-class set. Choose the one whose lowest note voice-leads best from your previous chord. Box V is a separate shape used for ♯11, alt, sus♭9 and minor-major colours.

Try these voicings in a tool

Pull up the Chord Finder for any chord in the tables above and you'll see the shape on the keyboard. Drill the cells against a click on the Chord Drill.

Voicing Boxes Series