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Piano chords

B half-diminished (Bm7b5) chord on piano

Half-diminished seventh chord (a diminished triad plus a minor seventh) on B: the notes of the Bm7b5 chord are B – D – F – A.

BDFA

Root position: B3 – D4 – F4 – A4

What the Bm7b5 chord sounds like

The half-diminished (m7b5) chord is a diminished triad with a minor seventh. In a minor key it sits on degree ii – the first chord of the minor ii–V–i.

Notes of the Bm7b5 chord

DegreeNoteInterval from the root
1Broot
3Dminor third (3 semitones)
5Fdiminished fifth (6 semitones)
7Aminor seventh (10 semitones)

Root position and inversions

An inversion uses the same notes, with a different note at the bottom. When you change chords, choosing the nearest inversion keeps your hand almost still.

Root position

B3 – D4 – F4 – A4

1st inversion

D4 – F4 – A4 – B4

2nd inversion

F4 – A4 – B4 – D5

3rd inversion

A4 – B4 – D5 – F5

Which keys is it in?

The Bm7b5 chord is built from the notes of these keys (for minor keys, both the natural and the harmonic minor are considered):

  • C major: viiø7
  • A minor: iiø7

Similar chords and substitutes

If Bm7b5 is too hard, or you want a different colour in the same spot, these chords are worth a try.

Substitutes (by function)

  • G9 – a rootless dominant ninth: the same notes over a root a major third lower
  • E7 – the next chord in a minor ii–V–i (V)

Same notes

  • Dm6 – 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 Bm7b5 chord?

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

How do I play the Bm7b5 chord on piano?

In root position, the right hand usually plays with fingers 1, 3 and 5 (thumb, middle finger, little finger); four-note chords with fingers 1, 2, 3 and 5. The left hand mirrors this: 5, 3, 1. In an inversion the top or bottom note moves to the other side, so your hand moves less when you change chords.

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.

Related chords

The same chord on another instrument:

Bm7b5 on guitarBm7b5 on ukuleleBm7b5 on mandolinBm7b5 on banjo

Other B chords on piano:

BBmB7Bmaj7Bm7Bsus2Bsus4B7sus4B6Bm6Badd9BdimBaugBdim7B9Bm9Bmaj9B11B13

All piano chords in a table →

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Photos: Isak Photography, 42 North, Rachel Loughman, Vitaly Gariev, Vitaly Gariev, Isaac Martin / Unsplash