What notes are in the Ab9 chord?

Ab9 is made of Ab, C, Eb, Gb and Bb — the 1, 3, 5, b7 and 9 degrees of a ninth chord built on Ab.

What keys use the Ab9 chord?

Every note of Ab9 belongs to 4 keys: Db Major (V), C# Major (V), Bb Minor (VII), A# Minor (VII). The roman numeral is the scale degree the chord is rooted on.

How do you play Ab9 on guitar and piano?

This page shows Ab9 on guitar, piano, ukulele and mandolin — 8 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.

Is Ab9 the same as G#9?

Yes. Ab9 and G#9 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Ab9 is the spelling this site treats as canonical.

Chord · Ab Dominant 9th

A♭9 Chord

A♭9 is Ab, C, Eb, Gb and Bb — funky, soulful; James Brown territory.

Hear it

A♭9 on every instrument

The same 5 notes, 4 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.

What A♭9 is made of

Ab Dominant 9th (Ab dominant 9th) is built from the notes Ab, C, Eb, Gb, Bb, with the interval pattern 1, 3, 5, b7, 9. A common dominant 9th chord across many styles.

Stack 1, 3, 5, b7 and 9 on a root of A♭ and you get Ab, C, Eb, Gb and Bb. That interval recipe is what makes the chord a ninth chord — move the same shape to another root and the character travels with it, which is why C9 sounds like a transposed A♭9.

Dominant 9th: Funky, soulful; James Brown territory.

Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with A♭ rather than its enharmonic equivalent.

Keys that contain A♭9

All 5 notes sit inside the scale of 4 keys. The roman numeral marks the degree the chord is rooted on.

Major keys

Minor keys

Other chords on A♭

Same root, different colour.

A♭Ab Major A♭augAb Augmented A♭sus2Ab Suspended 2nd A♭sus4Ab Suspended 4th A♭5Ab Power Chord A♭6Ab Major 6th A♭6/9Ab 6/9 A♭7Ab Dominant 7th

The same ninth shape, moved

The identical interval recipe, built on other roots.

C9C Dominant 9th D9D Dominant 9th E9E Dominant 9th F9F Dominant 9th G9G Dominant 9th A9A Dominant 9th B9B Dominant 9th F♯9F# Dominant 9th

Questions people ask about Ab9

What notes are in the Ab9 chord?: Ab9 is made of Ab, C, Eb, Gb and Bb — the 1, 3, 5, b7 and 9 degrees of a ninth chord built on Ab.
What keys use the Ab9 chord?: Every note of Ab9 belongs to 4 keys: Db Major (V), C# Major (V), Bb Minor (VII), A# Minor (VII). The roman numeral is the scale degree the chord is rooted on.
How do you play Ab9 on guitar and piano?: This page shows Ab9 on guitar, piano, ukulele and mandolin — 8 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Is Ab9 the same as G#9?: Yes. Ab9 and G#9 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Ab9 is the spelling this site treats as canonical.

Learn the theory behind it

Why A♭9 behaves the way it does — the guides that explain the chord instead of just spelling it.

Functional Harmony: Three Roles, One EngineWhat a seventh chord is for — tension, resolution, and the seat it takes in the key.6 min read The 12-Bar Blues — Three Chords, A Century of HitsSeventh chords are the whole sound of the blues. Twelve bars is where to hear it.7 min read