Tools / Chords / B♭ diminished

B♭ diminished chord on ukulele (B♭dim)

Also written B♭dim or B♭°

Ukulele · B♭dim/D♭ inversion

B♭ diminished contains B♭, D♭, and F♭. The open E string between two fretted notes gives this shape a quick, two-finger start.

B♭dim/D♭ inversion3-1-0-1

Positions on the neck1 of 5

How it’s built

B♭1Root

D♭♭3Minor 3rd

F♭♭5Diminished 5th

Formula 1, ♭3, ♭5

Positions on the neck1 of 5

Inversions

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

Root positionB♭–D♭–F♭B♭dimBass B♭

First inversionD♭–F♭–B♭B♭dim/D♭Bass D♭

Second inversionF♭–B♭–D♭B♭dim/F♭Bass F♭

Why it sounds like that

B♭ diminished is built from a root, a minor 3rd, and a diminished 5th. The diminished 5th between B♭ and F♭ creates the chord's tense, unstable quality. Compare it to B♭ minor, which raises the 5th to F natural.

What goes wrong with B♭ diminished?

Letting the middle finger touch the open E string, which deadens the chord.
Pressing the C string at the 1st fret so hard that the note goes sharp.

When to use it

B♭ diminished often substitutes for B♭ minor in progressions like B♭–E♭–F, the I–IV–V in B♭ major, to add tension before resolution. It suits jazz, blues, and dramatic pauses in ballads. Use it to lead into B♭ minor or C♯ major.

Changing to and from B♭ diminished

Move to <a href="/ukulele/b-flat-minor-chord">B♭ minor</a> by lifting the ring finger from the G string and placing it on the 3rd fret of the E string, while keeping the index and middle fingers in place.

Which voicing to use

The default voicing puts D♭ in the bass, giving a darker, more unstable sound. For a root-position feel, use the 9-10-9-× shape with B♭ in the bass, but it sits higher on the neck. The F♭ inversion at 6-4-6-4 brightens the chord with F♭ in the bass.

How do you play a B♭ diminished chord on ukulele?

B♭dim/D♭ inversion

Beginner● On the diagram

B♭ diminished is played in open position as 3 1 0 1: ring finger on the G string at fret 3, index finger on the C string at fret 1 and middle finger on the A string at fret 1. The E string rings open.

Tip — The ring finger must reach the 3rd fret on the G string while the index and middle fingers stay at the 1st fret without muting the open E string.

String-by-string breakdown

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

B♭dim/F♭ inversion · fret 4

Intermediate

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

String-by-string breakdown

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

B♭dim/F♭ inversion · fret 3

Intermediate

B♭ diminished is played at the 3rd fret as 3 4 6 4: index finger on the G string at fret 3, middle finger on the C string at fret 4, pinky finger on the E string at fret 6 and ring finger on the A string at fret 4.

String-by-string breakdown

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

9th fret

Intermediate

B♭ diminished is played at the 9th fret as 9 10 9 ×: index finger on the G string at fret 9, ring finger on the C string at fret 10 and middle finger on the E string at fret 9. The A string stays muted.

String-by-string breakdown

String	Fret	Finger	Note
4 (G)	9	1	F♭ (♭5)
3 (C)	10	3	B♭ (1)
2 (E)	9	2	D♭ (♭3)
1 (A)	muted	—	—

B♭dim/F♭ inversion · open position

Beginner

B♭ diminished is played in open position as 3 4 0 4: index finger on the G string at fret 3, middle finger on the C string at fret 4 and ring finger on the A string at fret 4. The E string rings open.

String-by-string breakdown

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

Common questions

How is B♭ diminished written?

B♭ diminished is written as B♭° or B♭dim. The ASCII root is Bb, so you may see Bbdim. It is also spelled A♯ in enharmonic notation for the same sounding root.

What is the difference between B♭ diminished and B♭ minor?

B♭ diminished lowers the 5th from F to F♭, creating a diminished 5th interval. B♭ minor has a perfect 5th, giving it a more stable, consonant sound.

Can I play B♭ diminished higher up the neck?

Yes, the shape at 9-10-9-× puts B♭ in the bass and works well for brighter passages. The 6-4-6-4 voicing uses F♭ in the bass for a different inversion.

String

Fret

Finger

Note

4 (G)

B♭ (1)

3 (C)

D♭ (♭3)

2 (E)

open

—

F♭ (♭5)

1 (A)

B♭ (1)

String

Fret

Finger

Note

4 (G)

D♭ (♭3)

3 (C)

F♭ (♭5)

2 (E)

B♭ (1)

1 (A)

D♭ (♭3)

String

Fret

Finger

Note

4 (G)

B♭ (1)

3 (C)

F♭ (♭5)

2 (E)

B♭ (1)

1 (A)

D♭ (♭3)

String

Fret

Finger

Note

4 (G)

F♭ (♭5)

3 (C)

B♭ (1)

2 (E)

D♭ (♭3)

1 (A)

muted

—

String

Fret

Finger

Note

4 (G)

B♭ (1)

3 (C)

F♭ (♭5)

2 (E)

open

—

F♭ (♭5)

1 (A)

D♭ (♭3)