Bb Diminished 7th
Bbdim7
Notes
Bb · Db · Fb · Abb
Intervals
- RootBb (1P)
- Minor 3rdDb (3m)
- Diminished 5thFb (5d)
- Diminished 7thAbb (7d)
Fretboard
On the fretboard, E represents Fb, and Ab represents Abb.
Adjust labels, frets, and palette in the interactive view.
About
The B♭ fully diminished 7 (B♭–D♭–F♭–A♭♭) stacks four minor thirds, giving it a fully symmetrical structure. Each note can be respelled as a root — B♭°7 is enharmonically the same chord as D♭°7, F♭°7, and A♭♭°7 — meaning a single shape on the guitar can function as four different leading-tone chords depending on context. This flexibility makes dim7 especially useful as a passing or substitution chord, often resolving up a half step (here to C♭). All four tones carry the chord’s identity; the chord is defined by its symmetry, so removing any note weakens that quality. On guitar, one shape repeats identically every three frets. Compared to B♭m7♭5, dim7 is more unstable and dramatically tense.
Similar chords
Chords sharing two or more notes with this one, ranked by overlap.
Scales containing this chord
- B♭ Blues (deg 1)
- A♭ Diminished (deg 2)
- A♭ Harmonic Minor (II)
- A♭ Natural Minor (II)
- B Diminished (deg 8)
- B Major (VII)
- B Melodic Minor (VII)
- D Diminished (deg 6)
- D♭ Diminished (deg 6)
- D♭ Harmonic Minor (VI)
- D♭ Melodic Minor (VI)
- D♭ Natural Minor (VI)
- F Diminished (deg 4)
- F Harmonic Minor (IV)
- B♭ Locrian (I)
- A♭ Locrian (II)
- A♭ Phrygian (II)
- D♭ Dorian (VI)
- D♭ Locrian (VI)
- D♭ Phrygian (VI)
- E Lydian (IV)
- E♭ Locrian (V)
- E♭ Phrygian (V)
- F♯ Mixolydian (III)
Scales whose notes include every chord tone. Roman numeral marks the chord root’s position in the scale; dashed badges aren’t linked yet.