B Half Diminished
Notes:B – D – F – A
Formula:R-m3-d5-m7
Intervals:P1-m3-d5-m7
Scale Degrees:1-b3-b5-b7
Introduction
The B Half Diminished piano chord (Bm7b5) consists of the notes B, D, F, A. It is a diminished triad with an added minor 7th, giving it a dark, moody, and tense character commonly used in jazz and minor key progressions. Formula: R-m3-d5-m7 | Scale degrees: 1-b3-b5-b7.
Notes
B Half Diminished Inversions
| Position | Notes |
|---|---|
| Root Position | B4 – D5 – F5 – A5 |
| 1st Inversion | D5 – F5 – A5 – B5 |
| 2nd Inversion | F5 – A5 – B5 – D6 |
| 3rd Inversion | B4 – D5 – F5 – A4 |
Key Signature
The key of B Half Diminished has 5 sharps: F♯, C♯, G♯, D♯, A♯.
F♯C♯G♯D♯A♯
Theory: Intervals
Formula: R-m3-d5-m7
Intervals: P1-m3-d5-m7
The B Half Diminished is built by stacking intervals from the root note. The formula R-m3-d5-m7 describes the scale degrees used. The intervals P1-m3-d5-m7 show the distance between each note in the chord.
B Half Diminished — Frequently Asked Questions
What notes are in the B Half Diminished chord?
Bm7b5 contains: B, D, F, A. All white keys. Diminished triad with minor seventh.
How does Bm7b5 differ from Bdim7?
Minor seventh (A) vs diminished seventh (Ab).
How is Bm7b5 used?
ii chord in A minor (Bm7b5–E7–Am). Also the vii chord in C Major. Extremely common.
What songs use Half Diminished?
Bm7b5 is the vii in C Major — one of the most common half-diminished chords. Jazz standards.
How does Bm7b5 differ from Bm7?
Flatted fifth (F vs F#).
Is Bm7b5 the same as Dm6?
Same notes (B, D, F, A = D, F, A, B).
Practice Tips
- Bm7b5 is all white keys — the easiest half-diminished chord.
- Minor-key ii–V–i in A minor: Bm7b5 → E7 → Am.
- Bm7b5 and Dm6 are the same notes.
- Also the vii chord in C Major.
- One of the most common half-diminished chords.
- Compare with Bdim7 and Bm7.