Ab Diminished 7th
Abdim7
Notes
Ab · Cb · Ebb · Gbb
Intervals
- RootAb (1P)
- Minor 3rdCb (3m)
- Diminished 5thEbb (5d)
- Diminished 7thGbb (7d)
Fretboard
On the fretboard, B represents Cb, Eb represents Ebb, and F represents Gbb.
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About
The A♭ fully diminished 7 (A♭–C♭–E♭♭–G♭♭) stacks four minor thirds, giving it a fully symmetrical structure. Each note can be respelled as a root — A♭°7 is enharmonically the same chord as C♭°7, E♭♭°7, and G♭♭°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 B♭♭). 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 A♭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
- A♭ Diminished (deg 1)
- A♭ Melodic Minor (I)
- A Diminished (deg 8)
- C Diminished (deg 6)
- C Harmonic Minor (VI)
- E♭ Diminished (deg 4)
- E♭ Harmonic Minor (IV)
- E♭ Natural Minor (IV)
- F Blues (deg 2)
- F♯ Diminished (deg 2)
- F♯ Major (II)
- F♯ Melodic Minor (II)
- A♭ Dorian (I)
- B Lydian (VI)
- B♭ Phrygian (VII)
- D♭ Mixolydian (V)
- F Locrian (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.