B diminished seventh (Bdim7) chord on ukulele

Diminished seventh chord (three stacked minor thirds) on B: the notes of the Bdim7 chord are B – D – F – A♭.

Dots show:

Basic shapemedium

Position 4medium

Position 7medium

Position 10medium

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Chord finder Transposer Tuner

What the Bdim7 chord sounds like

A diminished seventh is three stacked minor thirds, so it is symmetrical: four different roots give the same notes. A dramatic, tense passing chord.

Notes of the Bdim7 chord

Degree	Note	Interval from the root
1	B	root
3	D	minor third (3 semitones)
5	F	diminished fifth (6 semitones)
7	A♭	diminished seventh (9 semitones)

How to play it – with fingering

Basic shape

String 1 (A): fret 2, little finger (B4)
String 2 (E): fret 1, middle finger (F4)
String 3 (C): fret 2, ring finger (D4)
String 4 (G): fret 1, index finger (A♭4)

Position 4

String 1 (A): fret 5, little finger (D5)
String 2 (E): fret 4, middle finger (A♭4)
String 3 (C): fret 5, ring finger (F4)
String 4 (G): fret 4, index finger (B4)

Position 7

String 1 (A): fret 8, little finger (F5)
String 2 (E): fret 7, middle finger (B4)
String 3 (C): fret 8, ring finger (A♭4)
String 4 (G): fret 7, index finger (D5)

Tuning: G C E A (the G string is higher than the C – standard re-entrant ukulele tuning). In the diagram, × means the string is not played, and a circle means an open string.

Which keys is it in?

The Bdim7 chord is built from the notes of these keys (for minor keys, both the natural and the harmonic minor are considered):

C minor: vii°7

Similar chords and substitutes

If Bdim7 is too hard, or you want a different colour in the same spot, these chords are worth a try.

Substitutes (by function)

G7 – an incomplete dominant: the diminished chord is the top of this seventh chord
C – where it leads (leading tone → root)

Same notes

Ddim7 – the same notes with a different root
Fdim7 – the same notes with a different root
A♭dim7 – the same notes with a different root

Simpler versions

Bdim – all 3 of its notes are in this chord

Frequently asked questions

What notes are in the Bdim7 chord?

B, D, F, A♭. The root is B; the intervals of the other notes from the root: minor third, diminished fifth, diminished seventh.

What is the easiest way to play Bdim7 on ukulele?

The easiest shape above is “Basic shape”. We show 4 shapes, from open and easy versions to movable barre shapes higher up the neck.

How do I read the chord diagram?

Strings run from the lowest (left) to the highest (right) – tick “Left-handed” to mirror it. Rows are frets; a number at the side shows the starting fret. Dots are fingers (1 index, 2 middle, 3 ring, 4 little), a long bar is a barre, × means don't play that string and ○ means play it open.

Why do some songbooks write H instead of B?

In German and Central European notation, H is the note B, and B is the note B♭. So a “B” chord in a German or Hungarian songbook is B♭ in English notation, and an “H” chord is B. Always check which notation your chord chart uses.