A♭ Augmented Seventh Chord

Chord Tones: A♭ Augmented Seventh Chord

Symbol: aug7, +7, 7♯5 — Formula: 1-3-♯5-♭7

DegreeNoteFrequency (A=440, Equal)
1 A♭4 415.305 Hz
3 C4 261.626 Hz
♯5 E4 329.628 Hz
♭7 G♭4 369.994 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolA♭aug7
All Common Symbolsaug7, +7, 7♯5
Interval Formula1-3-♯5-♭7
Harmonic Categoryunstable

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

Inversions

InversionNotes (low to high)Bass NoteSlash Notation
Root Position A♭4 C4 E4 G♭4 A♭ A♭ Augmented Seventh Chord
First Inversion C4 E4 G♭4 A♭4 C A♭ Augmented Seventh Chord/C
Second Inversion E4 G♭4 A♭4 C4 E A♭ Augmented Seventh Chord/E
Third Inversion G♭4 A♭4 C4 E4 G♭ A♭ Augmented Seventh Chord/G♭

Harmonic Function

The A♭ augmented 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 augmented seventh chord adds a minor seventh to the augmented triad, combining the restlessness of an augmented fifth with the tension of a dominant seventh. Used for maximum harmonic tension. The A♭ Augmented Seventh Chord specifically contains 4 notes: A♭, C, E, G♭ (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♭ Augmented Seventh Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Augmented Seventh Chord

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

Tuning Frequencies Across Temperaments

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

NoteEqual Temp.PythagoreanJust Intonation
A♭4 415.305 Hz 417.657 Hz 418.601 Hz
C4 261.626 Hz 260.740 Hz 261.626 Hz
E4 329.628 Hz 330.001 Hz 327.032 Hz
G♭4 369.994 Hz 371.251 Hz 367.911 Hz

Scales Containing the A♭ Augmented Seventh Chord

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