Abaug9

Q: What notes are in the Abaug9 chord?

The Abaug9 chord (Ab Aug 9) contains: Ab, C, E, Gb, Bb. Its interval structure is shown above in the Theory section.

Q: How do I build Abaug9 on the keyboard?

Take the root and add the remaining chord tones following the interval formula. The highlight shows chord content, while the inversion control changes which chord tone is in the bass.

Q: Which keys is Abaug9 found in?

The chord acts as a diatonic degree in several keys — they are marked on the circle of fifths in the "Harmonic context" block.

Q: What can I substitute for Abaug9?

A substitution depends on harmonic function and voice leading, not only on shared tones. Computed options appear in the "Substitutions" block and should be checked in context.

Ab Aug 9

Octaves

Musical context

ChordAbaugTriad

ChordAbaug9Ab Aug 9

ArpeggioAb majorBroken triad

ScaleAb major7 notes

KeyAb majorMajor key

ProgressionPop axisSequence

How the chord relates to the scale, mode, key and progression.

Theory

General info

Full name: Ab Aug 9
Symbol: Abaug9
Root: Ab
Quality: Aug 9

Chord notes

1Abroot

3Cmajor 3rd

#5Eaug 5th

b7Gbminor 7th

2Bbmajor 2nd

Functions & resolutions

Stability / tension: High tension — requires resolution
Most common resolutions: DbDb Major BbmBb Minor
Unstable degrees: 3C
4Db
resolves up to the resolution tonic
#5E
6F
resolves up to the tonic 3rd
6F
b7Gb
resolves down to the tonic 3rd
Main resolution: Abaug9source
DbDb Major
Dominant 7th Ab7 naturally resolves up a 4th to Db. It is the tritone between the chord's 3rd and 7th that creates this pull.
Other resolutions: Abaug9source
Deceptive resolution
BbmBb Minor
Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.
Abaug9source
Modal resolution
GbGb Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
Abaug9source
Jazz reharmonization
D7D Dominant 7
Tritone substitution: Ab7 can be replaced by D7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.
Abaug9source
Functional resolution
Absus4Ab Sus4
The dominant can resolve beyond the tonic: moving to IV (subdominant) or to a suspension (sus4) are common alternatives in pop and folk music.

Substitutions

Tritone substitution: D7D Dominant 7

Features

Character: Dominant, with 9th and augmented 5th
Characteristic interval: Augmented 5th (#5), 9th
Description: The augmented 5th destabilises the triadic core, the minor 7th preserves dominant function, and the major 9th extends the chord. The #5 alteration intensifies chromatic voice leading.
Application: V+ → I in jazz
Altered blues
Passing chords

Voicing & structure

Root position

v1Ab(Ab4)Bass

root

v2C(C5)M3from Ab

v3E(E5)M3from C

v4Gb(Gb5)M2from E

v5Bb(Bb5)M3from Gb

Harmony

Compatible scales

All chord tones are contained in these scales — use them for improvisation.

ScaleC Whole tone scale ScaleE Whole tone scale ScaleF# Whole tone scale ScaleG# Whole tone scale ScaleA# Whole tone scale ScaleD Whole tone scale ScaleC Enigmatic scale ScaleC Altered (super Locrian)ScaleE Lydian augmented ScaleG# Mixolydian ♭6

This chord on guitar 🎸

See how Abaug9 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

Relative key: FmF minor
Dominant: EbEb major
Subdominant: DbDb major
Key signature: 4 flats (Bb, Eb, Ab, Db)

What to learn next

ScaleAb Chromatic scaleScale to improvise over this chord PracticeChord trainerLock the fingering into muscle memory ProgressionChord progressionsHow this chord works inside real progressions

Recommended for you

Ab Chromatic scaleA scale related to this chord

Practice

Keyboard Trainer

Reinforce it in practice — play and name notes on the interactive keyboard.

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Test yourself

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What notes are in the Abaug9 chord?

How do I build Abaug9 on the keyboard?

Which keys is Abaug9 found in?

What can I substitute for Abaug9?