A♭ Diminished
Also Known As
Hear the A♭ Diminished chord played for you.
A♭°
A♭ – B – D
Formula:R-m3-d5
Intervals:P1-m3-d5
Scale Degrees:1-b3-b5
Introduction
The A♭ Diminished chord is a three-note chord made up of A♭, B, and D. It is built from a root, minor third, and diminished fifth.
The Ab Diminished piano chord (Abdim) consists of the notes Ab, B, D. It is built by stacking two minor thirds (3 semitones each), giving it a tense, unstable, and dissonant character. Formula: R-m3-d5 | Scale degrees: 1-b3-b5.
Notes
A♭ Diminished Inversions
| Position | Notes |
|---|---|
| Root Position | Ab4 – B4 – D5 |
| 1st Inversion | B4 – D5 – Ab5 |
| 2nd Inversion | D5 – Ab5 – B5 |
Key Signature
The key of Ab 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
Intervals: P1-m3-d5
The A♭ Diminished is built by stacking intervals from the root note. The formula R-m3-d5 describes the scale degrees used. The intervals P1-m3-d5 show the distance between each note in the chord.
A♭ Diminished — Frequently Asked Questions
What notes are in the Ab Diminished chord?
The Ab Diminished chord contains: Ab (root), Cb (minor third), and Ebb (diminished fifth). Both intervals are compressed: the minor third is 3 semitones above the root, and the diminished fifth is 6 semitones — a tritone.
How does Ab Diminished differ from Ab Minor?
Ab Minor has a perfect fifth. Ab Diminished lowers the fifth by one semitone to Ebb (diminished fifth). That extra compression creates intense harmonic tension — the tritone between root and diminished fifth is the most dissonant interval in Western music.
What is the symbol for the Ab Diminished?
Ab Diminished is written as Abdim or Ab°. The ° or "dim" symbol means both the third and fifth are minor/diminished. Do not confuse with Abdim7 or Abø (half-diminished), which include additional notes.
What are the inversions of Ab Diminished?
First inversion (Ab Diminished/Cb): Cb–Ebb–Ab. Second inversion (Ab Diminished/Ebb): Ebb–Ab–Cb. Diminished triads are used in classical music as the vii° chord — the chord one semitone below the tonic, with strong resolution pull.
How is Ab Diminished used in music?
Ab Diminished most commonly functions as the vii° chord in a major key, creating strong resolution back to the tonic. It also works as a chromatic passing chord between two nearby chords, and in classical music as a brief point of dissonance. Jazz uses the full four-note dim7 more often than the triad.
What songs use diminished chords?
Michelle (Beatles) uses a diminished chord as a chromatic passing chord. Many classical pieces use vii°–I cadences. Jazz standards use dim7 chords as chromatic passing and approach chords. Diminished harmony also appears in flamenco and film music for dramatic tension.
Practice Tips
- Compare Ab Minor and Ab Diminished: only the fifth changes (Ebb vs perfect fifth). Play both back to back — the extra compression is striking.
- The tritone between Ab and Ebb creates maximum tension — practice just this two-note interval to hear its characteristic sound.
- Ab Diminished most naturally resolves up by half step: play Abdim then a chord whose root is Ab raised by one semitone.
- Practice all inversions: Ab–Cb–Ebb, Cb–Ebb–Ab, Ebb–Ab–Cb.
- Use Ab Diminished as a vii° chord: it is one semitone below Ab# Major — try Abdim → Ab# Major to feel this powerful classical resolution.
- In a major key, find where Ab Diminished fits naturally as a passing chord between two diatonic chords a step apart.
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.