A♭ Half Diminished
Also Known As
Hear the A♭ Half Diminished chord played for you.
A♭ø7
A♭ – B – D – G♭
Formula:R-m3-d5-m7
Intervals:P1-m3-d5-m7
Scale Degrees:1-b3-b5-b7
Introduction
The A♭ Half Diminished chord is a four-note chord made up of A♭, B, D, and G♭. It is built from a root, minor third, diminished fifth, and minor seventh.
The Ab Half Diminished piano chord (Abm7b5) consists of the notes Ab, B, D, Gb. It is a diminished triad with an added minor 7th, giving it a dark, moody, and tense character commonly used in jazz and minor key progressions. Formula: R-m3-d5-m7 | Scale degrees: 1-b3-b5-b7.
Notes
A♭ Half Diminished Inversions
| Position | Notes |
|---|---|
| Root Position | Ab – B – D – Gb |
| 1st Inversion | B – D – Gb – Ab |
| 2nd Inversion | D – Gb – Ab – B |
| 3rd Inversion | Ab – B – D – Gb |
Key Signature
The key of Ab Half Diminished has 4 flats.
B♭E♭A♭D♭
Order of flats
Flats are added in a fixed order — the reverse of the sharp order. Each new flat key adds the next flat on the list.
B♭E♭A♭D♭G♭C♭F♭
Mnemonic: Battle Ends And Down Goes Charles’ Father
Chords in the Key of Ab Major
These are the diatonic triads built on each degree of the Ab major scale:
C
D
E
F
G
A
B
C
D
E
F
G
A
B
I — A♭ Major (major)
Theory: Intervals
Formula: R-m3-d5-m7
Intervals: P1-m3-d5-m7
The A♭ Half Diminished is built by stacking intervals from the root note. The formula R-m3-d5-m7 describes the scale degrees used. The intervals P1-m3-d5-m7 show the distance between each note in the chord.
A♭ Half Diminished — Frequently Asked Questions
What notes are in the Ab Half Diminished chord?
Abm7b5 contains: Ab, Cb, Ebb, Gb. Diminished triad with minor seventh.
How does Abm7b5 differ from Abdim7?
Minor seventh (Gb) vs diminished seventh (Gbb/F).
How is Abm7b5 used?
ii chord in Gb minor.
What songs use Half Diminished?
Jazz minor-key harmony.
How does Abm7b5 differ from Abm7?
Flatted fifth (Ebb vs Eb).
Is Abm7b5 the same as Cbm6?
Same notes, different root.
Practice Tips
- Minor-key ii–V–i: Abm7b5 → Db7 → Gbm.
- Abm7b5 and Cbm6 same notes.
- Compare with Abdim7.
- Jazz vocabulary.
- Mostly black keys.
- The flatted fifth creates tension.
Related Tools
Chord FinderLook up any chord — see the notes, hear it, and play along.Chord DrillTimed drills to build speed and recognition across all chord types.Practice RoomPlug in a MIDI keyboard and get real-time feedback on every chord and scale.Circle of FifthsVisualize key relationships, relative minors, and key signatures.MIDI MonitorLive MIDI message stream with note names, velocity, and a scrolling staff.