Bdim7 chord on ukulele

Bdim7 is B, D, F and A♭. The usual shape is 1-2-1-2. Press Play to hear it, then try it at half speed.

1-2-1-2 · movable · medium

Notes: B · D · F · A♭
Formula: 1 · ♭3 · ♭5 · ♭♭7
First shape: 1-2-1-2

How to play Bdim7 on ukulele

Shape 1, 1-2-1-2, reading from the G string on the left:

Index finger: G string, 1st fret (A♭).
Middle finger: E string, 1st fret (F).
Ring finger: C string, 2nd fret (D).
Pinky: A string, 2nd fret (B).

The pinky takes a note here. Keep it curved and close to the fretboard between chords so it has less distance to travel.
Strum with the pad of your index finger or thumb, all four strings, across the spot where the neck meets the body.

Other ways to play Bdim7

4-5-4-5: movable shape at the 4th fret, medium. Use it when the next chord sits nearby on the neck.
7-8-7-8: movable shape at the 7th fret, medium. Up the neck the chord gets thinner and brighter, a good contrast to the open version.
10-11-10-11: movable shape at the 10th fret, medium. Up the neck the chord gets thinner and brighter, a good contrast to the open version.

Changing from Bdim7 to the chords around it

These are the changes you'll meet most often with Bdim7, using the first shape of each chord.

C (leads up a half step): Bdim7 (1-2-1-2) to C (0-0-0-3): move the index finger to the A string, 3rd fret. C on ukulele
Cm (leads up a half step): Bdim7 (1-2-1-2) to Cm (0-3-3-3): move the index finger to the C string, 3rd fret, the middle finger goes to the E string, 3rd fret, your ring finger lands on the A string, 3rd fret. Everything moves: lift the whole hand and place the new shape in one go. Cm on ukulele
E (a fifth down): Bdim7 (1-2-1-2) to E (1-4-0-2): your index finger stays put, your middle finger lands on the A string, 2nd fret, move the ring finger to the C string, 4th fret. Shared notes: B and A♭. E on ukulele

Bdim7 is a diminished seventh: three minor thirds stacked, so the chord divides the octave into four equal parts. All 4 notes of Bdim7 fit on the ukulele's four strings. Play it once strummed and once picked to hear the difference.

Practice Bdim7 in two minutes

Before strumming, play 1-2-1-2 note by note: A♭ then D then F then B. A dead note tells you exactly which finger to fix. Next, alternate 1-2-1-2 and 4-5-4-5, slowly, until the change takes less than a beat.

Bdim7 in context

Bdim7 on guitar and piano

The same notes on another instrument: Bdim7 on guitar and Bdim7 on piano. This page puts all three side by side.

Close to Bdim7

Other diminished seventh chords

Bdim7 on ukulele: questions

What notes are in Bdim7 on ukulele?

B, D, F and A♭. In the 1-2-1-2 shape the strings play A♭ (G string), D (C string), F (E string) and B (A string).

What's the easiest way to play Bdim7 on ukulele?

In standard tuning Bdim7 can't use open strings. Begin with 1-2-1-2. It uses 4 fingers and no barre, and a capo can make it easier in some songs.

Is Bdim7 a barre chord on ukulele?

Not usually: 1-2-1-2 needs no barre.

Which string does Bdim7 start on?

In the 1-2-1-2 shape the lowest string you play is the G string at the 1st fret, which is A♭, the diminished seventh.

Every shape above plays only B, D, F and A♭, checked by the site's tests. Updated September 2026.