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A♭ Diminished

Reviewed for accuracy · Last updated June 2026 · Maintained by Justin Evans

G♯ Diminished
This is the same chord as G♯ Diminished — the same keys on the keyboard, spelled with sharps.
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A♭°
A♭ – C♭ – E♭♭
Formula:R-m3-d5
Intervals:P1-m3-d5
Scale Degrees:1-b3-b5

Practice A♭ Diminished

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Introduction

Ab Diminished piano chord, root position — Ab, B, D
The Ab Diminished chord in root position on a piano keyboard, notes Ab, B, D.

The A♭ Diminished chord is a three-note chord made up of A♭, C♭, and E♭♭. It is built from a root, minor third, and diminished fifth.

Notes

Notes:A♭ – C♭ – E♭♭

A♭ Diminished Inversions

Ab Diminished piano chord, 1st inversion — B, D, Ab
The Ab Diminished chord, 1st inversion, on a piano keyboard.
Ab Diminished piano chord, 2nd inversion — D, Ab, B
The Ab Diminished chord, 2nd inversion, on a piano keyboard.
PositionNotes
Root PositionA♭ – C♭ – E♭♭
1st InversionC♭ – E♭♭ – A♭
2nd InversionE♭♭ – A♭ – C♭

Key Signature

A Diminished chord is built from symmetrical or ambiguous intervals, so it doesn’t belong to a single key and has no key signature of its own.

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 is the A♭ Diminished chord on piano?
The A♭ Diminished chord contains the notes A♭ – C♭ – E♭♭. On piano, play these notes together to sound the chord.
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.

References & Further Reading

How this chord page is sourced & verified

The note names, intervals, fingering, and harmony on this page are drawn from the established body of Western music theory and verified against the conventions below — the same fundamentals taught in conservatories and music programs. We list categories of source material rather than individual titles, and reference the standards themselves rather than any single edition.

  • Standard music theory texts — Widely taught fundamentals of pitch, rhythm, and notation.
  • Western tonal harmony conventions — Established rules for chord construction, voice leading, and key relationships.
  • Interval and chord construction standards — The conventional spelling of intervals, triads, sevenths, and extensions.
  • Scale and mode theory — The common derivation of major, minor, pentatonic, blues, and modal scales.
  • Piano pedagogy and technique references — Long-standing practices for fingering, hand position, and practice.

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