Ab7#9

Q: What notes are in the Ab7#9 chord?

The Ab7#9 chord (Ab 7#9) contains: Ab, C, Eb, Gb, B. Its interval structure is shown above in the Theory section.

Q: How do I build Ab7#9 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 Ab7#9 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 Ab7#9?

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 7#9

Octaves

Musical context

ChordAb majorTriad

ChordAb7#9Ab 7#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 7#9
Symbol: Ab7#9
Root: Ab
Quality: 7#9

Chord notes

1Abroot

3Cmajor 3rd

5Ebperfect 5th

b7Gbminor 7th

#2Baug 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
6F
b7Gb
resolves down to the tonic 3rd
#2B
4Db
resolves to the resolution tonic
Main resolution: Ab7#9source
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: Ab7#9source
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.
Ab7#9source
Modal resolution
GbGb Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
Ab7#9source
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.
Ab7#9source
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 an augmented 9th
Characteristic interval: Minor 7th (b7), Augmented 9th (#9)
Description: The augmented 9th is enharmonically equivalent to a minor 3rd and sounds alongside the chord’s major 3rd. Their chromatic clash creates sharp tension characteristic of blues and rock.
Application: Blues rock (Jimi Hendrix "Purple Haze")
Funk
Jazz fusion

Voicing & structure

Root position

v1Ab(Ab4)Bass

root

v2C(C5)M3from Ab

v3Eb(Eb5)m3from C

v4Gb(Gb5)m3from Eb

v5B(B5)P4from Gb

Harmony

Compatible scales

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

ScaleC Hungarian minor ScaleE Harmonic major ScaleG Double harmonic ScaleG Persian scale ScaleG Byzantine ScaleC Diminished scale ScaleD# Diminished scale ScaleD# Bebop melodic minor ScaleF# Diminished scale ScaleG# Diminished (half–whole)

This chord on guitar 🎸

See how Ab7#9 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 Ab7#9 chord?

How do I build Ab7#9 on the keyboard?

Which keys is Ab7#9 found in?

What can I substitute for Ab7#9?