B half-diminished (m7♭5)
How to play Bm7♭5 — Half-diminished (m7♭5)
Bm7♭5 (Half-diminished (m7♭5))B · D · F · A
Piano samples: Salamander Grand Piano (CC-BY 3.0)
B half-diminished (m7♭5) — notes and structure
The Bm7♭5 chord is the half-diminished chord: a minor seventh with a flattened fifth, the key ii chord of minor ii–V–i progressions.
The Bm7♭5 half-diminished (m7♭5) consists of the notes B, D, F, A. Its interval structure is R–3–5–7 — the root, then each chord tone stacked above it. This is the same chord you see in the interactive finder above, drawn on the piano keyboard with the root circled and every chord tone labelled.
Bm7♭5 stacks a minor third (D), a diminished fifth (F) and a minor seventh (A) above the root B.
To play Bm7♭5, press the keys B, D, F, A together — the root B is circled on the interactive keyboard above.
What key is Bm7♭5 in?
Every note of Bm7♭5 belongs to the scales below, so the chord sounds at home in each of these keys — the roman numeral is the degree it sits on.
- C major — the vii° chord
- A minor — the ii° chord
Chords that go with Bm7♭5
In C major, the chords built on the first, fourth and fifth degrees carry most songs — put Bm7♭5 next to these:
Frequently asked questions
- What notes are in the B half-diminished (m7♭5) chord on piano?
- The Bm7♭5 chord is made of the notes B, D, F, A. It is the half-diminished chord: a minor seventh with a flattened fifth, the key ii chord of minor ii–V–i progressions.
- How do you play B half-diminished (m7♭5) on the piano?
- Press B, D, F, A at the same time, with the root B as the lowest note. The interactive keyboard above lights up the exact keys.
- What is the half-diminished (m7♭5) chord formula?
- Its interval structure is R–3–5–7 above the root — the same shape transposed to any of the twelve keys.
- What key does Bm7♭5 belong to?
- Bm7♭5 fits C major (where it is the vii° chord), A minor (where it is the ii° chord) — every note of the chord is in those scales.