Bm7b5 Half-Diminished 7th Chord

The B Half-Diminished 7th chord contains: B, D, F, A.

These notes are derived by applying the half-diminished 7th interval formula (0–3–6–10 semitones) to the root note B.

Diminished triad with a minor seventh.

Common in jazz as the ii chord in minor keys. The Bm7b5 chord is used across pop, rock, jazz, and classical music. As the I chord in the key of B major, it functions as the most stable resting point in progressions.

On piano, play B, D, F, A simultaneously.

In root position, B is the lowest note. Inversions move the bass note up — first inversion has D lowest, second inversion has F lowest.

A half-diminished 7th chord has 4 notes: B, D, F, A (in B).

It is a 7th chord, extending beyond the basic triad.

The B major chord (B–D#–F#) uses a major third (4 semitones), giving it a bright, happy sound.

The B minor chord (B–D–F#) uses a minor third (3 semitones), giving it a darker, emotional sound.

Bm7b5 naturally serves as the I chord in the key of B major.

It also appears as IV in the key of F# major, and as V in the key of E major.

Yes.

The ukulele uses GCEA tuning with 4 strings. The Bm7b5 chord notes (B, D, F, A) can be fretted on a ukulele, though the shapes differ from guitar due to the 4-string layout and shorter scale.

In the key of B major, Bm7b5 pairs naturally with E major (IV), F# major (V), and G#m (vi).

The classic I–IV–V (Bm7b5–E–F#) is the foundation of blues, country, and rock.

An inversion places a non-root note in the bass.

Bm7b5 root position: B in bass. First inversion: D in bass. Second inversion: F in bass. Inversions create smoother bass line movement without changing the harmony.

Remember the formula: 0–3–6–10 semitones from root.

For Bm7b5: start on B, add 3 semitones, then 6 semitones, then 10 semitones. Practicing this across all 12 roots builds instant recognition of any half-diminished 7th chord.