A♭ Diminished Seventh Chord

Chord Tones: A♭ Diminished Seventh Chord

Symbol: dim7, °7 — Formula: 1-♭3-♭5-𝄫7

Chord Notation

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

Harmonic Function

The A♭ diminished seventh chord commonly functions as the submediant (♭VI) in C minor or subdominant in E♭ major. Its harmonic role varies by key — in major keys it provides extended harmonic tension.

The diminished seventh chord consists of four equally-spaced minor thirds, creating a symmetrical, highly dissonant chord. It is used as a dramatic pivot chord and in chromatic passing harmony. The A♭ Diminished Seventh Chord specifically contains 4 notes: A♭, B, D, F (formula: 1-♭3-♭5-𝄫7). On piano, Ab-rooted chords use a combination of black and white keys that creates a relaxed hand shape, favored by Romantic-era composers for lyrical passages. Pop ballads, film scores, and neo-soul tracks often use Ab chords for their warm, enveloping quality — the key sits comfortably for many vocal ranges.

Common Progressions

The A♭ Diminished Seventh Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

• viidim7-I
• sharpivdim7-V

Songs Featuring the Diminished Seventh Chord

Well-known songs where the A♭ Diminished Seventh Chord — or this chord type — plays a prominent role:

• While My Guitar Gently Weeps – Beatles
• Georgia on My Mind – Ray Charles
• Sophisticated Lady – Duke Ellington

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

Scales Containing the A♭ Diminished Seventh Chord

These scales include the A♭ Diminished Seventh Chord as a diatonic or characteristic chord: