Abdim7(b9) Diminished
The Abdim7(b9) chord is built from the notes Ab – Cb – Ebb – Gbb – Bbb.
Piano sound loads on first tap.
Also known as
Abdim7addb9Abo(addb9)Abo7(addb5b9)Abo7(b9)
Chord tones, one by one
AbRoot
Root
The fundamental note the chord is built on — Ab.
CbThird
Minor third
Three semitones — makes the chord minor (darker, sadder).
EbbFifth
Diminished fifth (♭5)
Six semitones — a flat fifth. Creates instability, typical of m7♭5 and diminished chords.
GbbSeventh
Diminished seventh (♭♭7)
Nine semitones — a doubly-flat seventh, found in fully diminished 7th chords.
BbbExtension
Flat ninth (♭9)
A ♭9 — sharp, dissonant tension typical of altered dominant chords.
🎼 Related scales
Locrian ♮6harmonic minor a semitone below
🎹 Modal analysis
This chord implies the Locrian ♮6 scale; its characteristic note is the natural 6th over a diminished chord. It is a mode of the harmonic minor a semitone below.
🎸 Genres
Modern jazz · Post-bop · Fusion