B diminished chord (Bdim)

B diminished is a 3-note diminished chord: B – D – F. It sounds unstable and tense. Here it is on guitar, piano and ukulele, with fingering and audio.

NotesB – D – F
Formula1 – ♭3 – ♭5
SymbolBdim · B° · Bm♭5
TypeDiminished chord

B diminished on guitar

Fret 2 (A shape)
Fret 9 (D shape)

How to place your fingers (fret 2)

Finger 1 (index) on fret 2 of the 5th string (A).
Finger 2 (middle) on fret 3 of the 4th string (D).
Finger 4 (pinky) on fret 4 of the 3rd string (G).
Finger 3 (ring) on fret 3 of the 2nd string (B).
Do not play the 6th and 1st strings: strum from the 5th string.

The numbers inside the dots are the fingers of your left hand: 1 index, 2 middle, 3 ring and 4 pinky. The colored dots mark the root (B). The other positions let you change chords without jumping along the neck, or give you a higher-pitched sound.

B diminished on piano

In root position, play B – D – F from bottom to top with fingers 1, 3 and 5 of your right hand (thumb, middle and pinky). With your left hand you usually play just the root (B) or the root and the fifth.

Inversions

First inversion: D – F – B
Second inversion: F – B – D

B diminished on ukulele

From fret 1
From fret 4

Standard tuning G – C – E – A (the G string is the high one). Is your ukulele in tune? Use the ukulele tuner.

Notes and intervals of B diminished

B1 · root
D♭3 · minor third
F♭5 · diminished fifth

It's the seventh degree of the major scale and works as a passing chord between two chords a whole step apart.

Progressions with Bdim

A leading tone that resolves: vii° – I

Bdim is the seventh degree of C major and leads to C.

Passing chord: I – ♯i° – ii

It climbs by half steps between two chords a whole step apart.

Which keys contain B diminished?

Bdim belongs to 2 keys: in each one it plays a different role depending on the degree (the Roman numeral).

Key	Degree
C major	vii°
A natural minor	ii°

Frequently asked questions

What notes are in the B diminished chord?

B diminished (Bdim) has 3 notes: B (root), D (minor third), F (diminished fifth).

How do you play B diminished on guitar?

The most common shape starts at fret 2: x 2 3 4 3 x (from the 6th to the 1st string). Finger 1 (index) on fret 2 of the 5th string (A). Finger 2 (middle) on fret 3 of the 4th string (D). Finger 4 (pinky) on fret 4 of the 3rd string (G). Finger 3 (ring) on fret 3 of the 2nd string (B). Don't play the 6th and 1st strings: strum from the 5th.

What is the chord symbol for B diminished?

It is written Bdim; you may also see B° or Bm♭5. Letter notation uses C, D, E, F, G, A, and B for the notes.

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