Bdim7 chord
Bdim7 is B, D, F and A♭: 1–♭3–♭5–♭♭7 built on B. Here it is on guitar, piano and ukulele. Tap Play on any of them.
On guitar
x-2-0-1-0-1 · open · easy
- Notes
- B · D · F · A♭
- Formula
- 1 · ♭3 · ♭5 · ♭♭7
- First shape
- x-2-0-1-0-1
Bdim7 on guitar: every shape, finger by finger
On piano
root position · B–D–F–A♭ · right hand 1-2-3-5
- Notes
- B · D · F · A♭
- Formula
- 1 · ♭3 · ♭5 · ♭♭7
Bdim7 on piano: fingering and inversions
On ukulele
1-2-1-2 · movable · medium
- Notes
- B · D · F · A♭
- Formula
- 1 · ♭3 · ♭5 · ♭♭7
- First shape
- 1-2-1-2
Changing out of Bdim7
Three changes cover most of what Bdim7 does in songs.
- Bdim7 → C (leads up a half step)
Guitar: Bdim7 (x-2-0-1-0-1) to C (x-3-2-0-1-0): the index finger slides across to the B string at the same fret, the middle finger goes to the D string, 2nd fret, your ring finger lands on the A string, 3rd fret. No finger can stay, so practice lifting all of them together and landing the new shape as a unit.
Piano: Bdim7 to C: play C in root position (C–E–G), while B moves up to C, F down to E and A♭ down to G. C - Bdim7 → Cm (leads up a half step)
Guitar: Bdim7 (x-2-0-1-0-1) to Cm (x-3-1-0-1-3): the index finger slides across to the D string at the same fret, the middle finger slides across to the B string at the same fret, your ring finger lands on the A string, 3rd fret, the pinky finger comes down on the high E string, 3rd fret. Nothing carries over, so drill it slowly, lifting and landing all fingers at once.
Piano: Bdim7 to Cm: play Cm in root position (C–E♭–G), while B moves up to C, D up to E♭ and A♭ down to G. Cm - Bdim7 → E (a fifth down)
Guitar: Bdim7 (x-2-0-1-0-1) to E (0-2-2-1-0-0): your index finger stays put, your middle finger lands on the A string, 2nd fret, the ring finger slides across to the D string at the same fret. B and A♭ carry over from one chord to the other.
Piano: Bdim7 to E: play E in 2nd inversion (B–E–G♯) and B and G♯ stay under the same fingers, while F moves down to E. E
How Bdim7 is built
Bdim7 is a diminished seventh: three minor thirds stacked, so the chord divides the octave into four equal parts. That symmetry means Bdim7 contains exactly the same four notes as Ddim7, Fdim7 and G♯dim7; which name you use depends on the bass note and the key.
From B, go 3 half steps up to D, 3 half steps up to F then 3 half steps up to A♭.
| Note | Role | Half steps | Hear it |
|---|---|---|---|
| B | root | 0 | |
| D | minor third | 3 | |
| F | diminished fifth | 6 | |
| A♭ | diminished seventh | 9 |
Keys and progressions with Bdim7
Bdim7 isn't a chord of any major or natural minor key, so it usually appears as a passing or borrowed chord.
Chords close to Bdim7
- Bdim7 is Bdim plus A♭. Bdim
Chords that share most of their notes with Bdim7: Ddim7, Fdim7, G♯dim7, Ddim, Fdim, G♯dim.
Every B chord
Bdim7 chord: questions
What notes are in the Bdim7 chord?
B, D, F and A♭. Bdim7 is built 1–♭3–♭5–♭♭7 from B: D is the minor third, F is the diminished fifth and A♭ is the diminished seventh.
How do you play Bdim7 on guitar?
The usual shape is x-2-0-1-0-1 (open). All 4 guitar shapes.
How do you play Bdim7 on piano?
Play B, D, F and A♭ with right-hand fingers 1-2-3-5. B sits just right of the group of three black keys. Inversions and left hand.
How do you play Bdim7 on ukulele?
1-2-1-2 in standard GCEA tuning. More ukulele shapes.
What key is Bdim7 in?
Bdim7 isn't a chord of any major or natural minor key, so it usually appears as a passing or borrowed chord.
What's the difference between Bdim7 and Bdim?
Bdim7 is Bdim plus A♭.
All three instruments are drawn and played from B, D, F and A♭ by the same engine. Updated September 2026.