What notes are in a B half-diminished chord?

B half-diminished contains four notes: B (root), D (minor third), F (diminished fifth), and A (minor seventh).

How does Bm7♭5 resolve?

In A minor: Bm7♭5 → E7 → Am. The chord prepares the dominant E7, which resolves to the Am tonic. This is one of the most-used cadences in tonal music.

Is Bm7♭5 the same as Bm7?

No — different chords. Bm7 (B-D-F♯-A) has a perfect fifth; Bm7♭5 (B-D-F-A) lowers that fifth a half step, producing the half-diminished colour and the iiø7 function in A minor.

Where does B half-diminished appear in famous music?

Throughout A-minor literature: Bach's A-minor preludes and fugues, Mozart's K. 310 sonata, Beethoven's "Moonlight" Sonata third movement (in C♯ minor but borrowing related sonorities), and every A-minor jazz standard.

B half-diminished chord — notes, intervals, and practice

B half-diminished (Bm7♭5 or Bø) — B, D, F, A — is the iiø7 of A minor and one of the most common half-diminished chords in standard repertoire. As the iiø7 of A minor — a key in which Bach, Mozart, Beethoven, and countless jazz musicians wrote — Bm7♭5 appears at the primary cadences of an enormous slice of Western music.

Intervals

The B half-diminished chord stacks two thirds on the root. Each interval and its size in semitones:

B→Dminor 3rd3 semitones
D→Fminor 3rd3 semitones
F→Amajor 3rd4 semitones

On the keyboard

Each note of the B half-diminished chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the B half-diminished chord on a six-string guitar fretboard.

Common mistakes

Bm7♭5 has all naturals: B-D-F-A. No sharps, no flats — the cleanest half-diminished spelling on the page. The most common error is reading F as F♯, which makes Bm7 (regular minor seventh, no flat fifth); the half-diminished colour requires the lowered fifth (F natural). On guitar, Bm7♭5 is a common closed-position chord on the upper strings — easier to finger than many half-diminished voicings.

In context

Bm7♭5 → E7 → Am is the ii–V–i in A minor — used in countless classical works (Bach's A-minor literature is full of it) and in every A-minor jazz standard. Mozart's K. 310 piano sonata, Beethoven's "Pathétique" (which uses related half-diminished colours), and "Autumn Leaves" (in the relative-minor cadence) all rely on this chord.

Drill it

The B half-diminished chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in a B half-diminished chord?: B half-diminished contains four notes: B (root), D (minor third), F (diminished fifth), and A (minor seventh).
How does Bm7♭5 resolve?: In A minor: Bm7♭5 → E7 → Am. The chord prepares the dominant E7, which resolves to the Am tonic. This is one of the most-used cadences in tonal music.
Is Bm7♭5 the same as Bm7?: No — different chords. Bm7 (B-D-F♯-A) has a perfect fifth; Bm7♭5 (B-D-F-A) lowers that fifth a half step, producing the half-diminished colour and the iiø7 function in A minor.
Where does B half-diminished appear in famous music?: Throughout A-minor literature: Bach's A-minor preludes and fugues, Mozart's K. 310 sonata, Beethoven's "Moonlight" Sonata third movement (in C♯ minor but borrowing related sonorities), and every A-minor jazz standard.