B diminished chord
The chord nobody strums. Three notes that are only there to resolve.
- How it sounds
- Tense and unstable. It has a flat fifth where a perfect one should be, so nothing in it sits still. It’s G7 without the G and behaves like it: every note leans toward C.
- Where it lives
- The vii° of C major and the ii° of A minor. Rarely a chord you stay on: a passing chord between C and Am, or a lighter stand-in for G7 before the tonic. Jazz voicings, classical harmony, gospel turnarounds.
Voicings across the neck
B, D and F are shown in four places on the neck. Every grip uses four strings, so one note is always doubled, and each takes its name from the string its root sits on. Mute the other two. The G-root form at the 1st fret and the A-root form at the 2nd sit close to the open C and Am, the chords B diminished usually passes between. The E-root form at the 7th and the D-root at the 9th give you the same chord higher up.
- High E string: F at fret 1
- B string: D at fret 3
- G string: B at fret 4
- D string: F at fret 3
- A string: not played
- Low E string: not played
- High E string: not played
- B string: D at fret 3
- G string: B at fret 4
- D string: F at fret 3
- A string: B at fret 2
- Low E string: not played
- High E string: not played
- B string: not played
- G string: D at fret 7
- D string: B at fret 9
- A string: F at fret 8
- Low E string: B at fret 7
- High E string: D at fret 10
- B string: B at fret 12
- G string: F at fret 10
- D string: B at fret 9
- A string: not played
- Low E string: not played
Formula
| Intervals | Notes | Semitones |
|---|---|---|
| R · m3 · d5: what each interval does in a chord | B · D · F | 3 + 3 |
B diminished is a root, a minor third and a diminished fifth: B, D and F. Start on the seventh note of C major and skip every other one, and you get these three, the only diminished chord in the key. Both gaps are three frets. Raise F a fret to F♯ and it turns into B minor.
In these keys and scales
B diminished turns up in six scales on the site, half as many as C or Am, and it’s home in none of them. In C major it’s the vii°, a fret below C. In A minor and A harmonic minor it’s the ii°. C harmonic minor and C melodic minor both raise their seventh note to B, so it’s their vii° too, and in D melodic minor it’s the vi°. The numeral beside each scale names the job, and the name opens that scale’s page.
| Family | Scales |
|---|---|
| Major | |
| Natural minor | |
| Harmonic minor | |
| Melodic minor |
Progressions
B diminished is on its way somewhere in all three. In vii°–I, B rises a fret to C and the chord resolves. In I–vii°–vi it’s the middle step of a bass line walking down, C, B, A. In ii°–V–i it opens the minor cadence, and E major carries it the rest of the way to A minor.