Tools / Chords / B diminished major 7th

B diminished major 7th chord on ukulele (BdimMaj7)

Also written BdimMaj7, BdimM7 or B°M7

Ukulele · BdimM7/D inversion · B on top

B diminished major 7th contains B, D, F, and A♯. The default BdimM7/D inversion puts the minor 3rd in the bass and demands a wide pinky stretch.

BdimM7/D inversion · B on top3-2-1-2

Positions on the neck1 of 3

How it’s built

B1Root

D♭3Minor 3rd

F♭5Diminished 5th

A♯7Major 7th

Formula 1, ♭3, ♭5, 7

Positions on the neck1 of 3

Inversions

The same three notes, with a different one in the bass.

Root positionB–D–F–A♯BdimMaj7Bass B

First inversionD–F–A♯–BBdimMaj7/DBass D

Second inversionF–A♯–B–DBdimMaj7/FBass F

Third inversionA♯–B–D–FBdimMaj7/A♯Bass A♯

Why it sounds like that

B diminished major 7th is built from the formula 1, ♭3, ♭5, 7. The major 7th interval between B and A♯ gives it a sharp leading tone. Compare it to B minor 7th flat 5th, which lowers the 7th to A.

What goes wrong with B diminished major 7th?

Letting the pinky flatten and buzz the G string.
Muting the A string with the ring finger.

When to use it

B diminished major 7th works as a passing chord in B minor or B major contexts. Use it to lead into B minor or B major. Its tense sound suits jazz and gypsy minor lines.

Changing to and from B diminished major 7th

Sliding the shape up one fret to the 2nd fret gives C diminished major 7th.
Sliding the shape up two frets to the 3rd fret gives C♯ diminished major 7th.

Which voicing to use

The BdimM7/D inversion keeps the bass on D, which softens the root. The BdimM7/F inversion puts the diminished 5th in the bass for a darker edge.

How do you play a B diminished major 7th chord on ukulele?

BdimM7/D inversion · B on top

Intermediate● On the diagram

B diminished major 7th is played at the 1st fret as 3 2 1 2: pinky finger on the G string at fret 3, middle finger on the C string at fret 2, index finger on the E string at fret 1 and ring finger on the A string at fret 2.

Tip — The pinky must reach the 3rd fret on the G string while the other fingers hold a close cluster.

String-by-string breakdown

String	Fret	Finger	Note
4 (G)	3	4	A♯ (7)
3 (C)	2	2	D (♭3)
2 (E)	1	1	F (♭5)
1 (A)	2	3	B (1)

BdimM7/F inversion

Intermediate

B diminished major 7th is played at the 4th fret as 4 5 6 5: index finger on the G string at fret 4, middle finger on the C string at fret 5, pinky finger on the E string at fret 6 and ring finger on the A string at fret 5.

String-by-string breakdown

String	Fret	Finger	Note
4 (G)	4	1	B (1)
3 (C)	5	2	F (♭5)
2 (E)	6	4	A♯ (7)
1 (A)	5	3	D (♭3)

BdimM7/D inversion · A♯ on top

Barre

B diminished major 7th is played at the 1st fret as 4 2 1 1: barre your index finger across fret 1, ring finger on the G string at fret 4 and middle finger on the C string at fret 2.

String-by-string breakdown

String	Fret	Finger	Note
4 (G)	4	3	B (1)
3 (C)	2	2	D (♭3)
2 (E)	1	1 (barre)	F (♭5)
1 (A)	1	1 (barre)	A♯ (7)

Common questions

How is B diminished major 7th written?

B diminished major 7th is written B°M7 or BdimM7. It is also called augmented minor seventh or minor seventh sharp five.

What is the difference between B diminished major 7th and B minor 7th flat 5th?

B diminished major 7th has a major 7th (A♯), while B minor 7th flat 5th has a minor 7th (A). That one semitone changes the chord's color completely.

Why does B diminished major 7th sound so tense?

B diminished major 7th contains a tritone between B and F and a major 7th between B and A♯. Both intervals create strong dissonance that wants to resolve.

String

Fret

Finger

Note

4 (G)

A♯ (7)

3 (C)

D (♭3)

2 (E)

F (♭5)

1 (A)

B (1)

String

Fret

Finger

Note

4 (G)

B (1)

3 (C)

F (♭5)

2 (E)

A♯ (7)

1 (A)

D (♭3)

String

Fret

Finger

Note

4 (G)

B (1)

3 (C)

D (♭3)

2 (E)

1 (barre)

F (♭5)

1 (A)

1 (barre)

A♯ (7)