Chord · B Half-Diminished 7th (m7♭5)
Bm7♭5 Chord
Bm7♭5 is B, D, F and A — the ii in a minor ii-V-i.
Bm7♭5 on every instrument
The same 4 notes, 6 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.
What Bm7♭5 is made of
B Half-Diminished 7th (m7♭5) (B half-diminished 7th (m7♭5)) is built from the notes B, D, F, A, with the interval pattern 1, b3, b5, b7. A common half-diminished 7th (m7♭5) chord across many styles.
Stack 1, b3, b5 and b7 on a root of B and you get B, D, F and A. That interval recipe is what makes the chord a half diminished seventh chord — move the same shape to another root and the character travels with it, which is why Cm7♭5 sounds like a transposed Bm7♭5.
Half-Diminished 7th (m7♭5): The ii in a minor ii-V-i.
Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. Every tone here lands on its own letter — no accidentals needed.
Keys that contain Bm7♭5
All 4 notes sit inside the scale of 2 keys. The roman numeral marks the degree the chord is rooted on.
Major keys
Minor keys
Other chords on B
Same root, different colour.
The same half diminished seventh shape, moved
The identical interval recipe, built on other roots.
Questions people ask about Bm7b5
- What notes are in the Bm7b5 chord?
- Bm7b5 is made of B, D, F and A — the 1, b3, b5 and b7 degrees of a half diminished seventh chord built on B.
- What keys use the Bm7b5 chord?
- Every note of Bm7b5 belongs to 2 keys: C Major (vii°), A Minor (ii°). The roman numeral is the scale degree the chord is rooted on.
- How do you play Bm7b5 on guitar and piano?
- This page shows Bm7b5 on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Learn the theory behind it
Why Bm7♭5 behaves the way it does — the guides that explain the chord instead of just spelling it.