Ab Augmented 7th
Introduction
Enharmonic equivalent: A♭ is enharmonically equivalent to G♯. See G# Augmented 7th.
Notes
Ab Augmented 7th Inversions
| Position | Notes |
|---|---|
| Root Position | Ab4 – C5 – E5 – Gb5 |
| 1st Inversion | C5 – E5 – Gb5 – Ab5 |
| 2nd Inversion | E5 – Gb5 – Ab5 – C6 |
| 3rd Inversion | Ab4 – C5 – E5 – Gb4 |
Key Signature
The key of Ab Augmented 7th has 4 flats: B♭, E♭, A♭, D♭.
Theory: Intervals
The Ab Augmented 7th is built by stacking intervals from the root note. The formula R-M3-A5-m7 describes the scale degrees used. The intervals P1-M3-A5-m7 show the distance between each note in the chord.
Ab Augmented 7th — Frequently Asked Questions
What notes are in the Ab Augmented 7th chord?
The Ab Augmented 7th chord (Ab+7) contains four notes: Ab (root), C (major third), E (augmented fifth), and Gb (minor seventh). It combines an augmented triad with a minor seventh.
How does Ab Augmented 7th differ from Ab Dominant 7th?
Both contain Ab, C, and Gb. Ab+7 has E (augmented fifth) while Ab7 has Eb (perfect fifth). The raised fifth adds extra tension and upward pull.
How is Ab Augmented 7th used in music?
Ab+7 is an altered dominant resolving to Db Major. The E pulls up to F while Gb pulls down to F — converging on the third of Db. Common in jazz, R&B, and gospel in flat keys.
What genres use Augmented 7th chords?
Augmented 7th chords are common in jazz, gospel, blues, and R&B. Ab+7 appears in flat-key contexts popular with vocalists and horn players.
What songs use Augmented 7th chords?
Augmented 7th chords appear in jazz standards and gospel. Ab+7 resolves to Db Major, a key favoured in R&B and soul.
What is the difference between +7 and 7#5?
They are the same chord. Ab+7, Ab7#5, and Abaug7 all refer to Ab Augmented 7th.
Practice Tips
- Play Ab7 then raise Eb to E — hear the augmented fifth's chromatic tension.
- Practice Ab+7 → Db Major. E and Gb both resolve to F — converging voice leading.
- Compare Ab+7 with Ab7 — both resolve to Db, but +7 adds richer harmonic colour.
- In jazz: Bbm7 → Ab+7 → Dbmaj7 adds sophistication to the ii–V–I in Db.
- Ab+7 is powerful in R&B and gospel contexts where Db Major is a common key.
- The augmented triad (Ab–C–E) divides the octave into three equal major thirds.