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A♭7♯9 Chord: Guitar, Piano and Notes

The A♭7♯9 chord is a altered dominant seventh chord built on the root note A♭. Its notes are A♭, C, E♭, G♭ and B. It's enharmonically the same chord as G♯7♯9.

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Quality
Short answer

Dominant seventh sharp nine chords sound gritty and bluesy at once, the clash of a major third against a sharp ninth that reads to the ear like a minor third. Funk, rock and soul horn sections lean hard on this one chord.

Notes
A♭ · C · E♭ · G♭ · B
Formula
1 · 3 · 5 · ♭7 · ♯9
Semitones
0 · 4 · 7 · 10 · 15
Note
A♭
Quality
Dominant 7♯9
Symbol
A♭7♯9

A♭7♯9 on piano

5 notes
View:
Piano diagram of the A♭7♯9 chord

Switch to the interactive diagram to hear the chord, change voicing and swap finger numbers for note names.

To play A♭7♯9 on piano, place your right hand with your thumb on A♭, index finger on C, middle finger on E♭, ring finger on G♭ and little finger on B. Press the keys together and listen for an even sound. On the keyboard A♭, E♭ and G♭ are black keys and C and B are white. The thumb starts on a black key, so slide the whole hand a little further in, towards the fallboard. Practice moving in and out of the chord slowly, then bring in a metronome.

  • A♭1
  • C3
  • E♭5
  • G♭♭7
  • B♯9

A♭7♯9 on guitar

View:
Guitar chord diagram of the A♭7♯9 chord

Switch to the interactive diagram to hear the chord, change voicing and swap finger numbers for note names.

On guitar, A♭7♯9 is commonly played with the voicing shown above. This one is a barre at fret 1: keep the index finger flat across the strings and curve the others so they don't mute the strings next to them. String 2 rings open.

A♭ · C · E♭ · G♭ · B

Play A♭7♯9 on the online piano

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A♭7♯9 chord notes

Also known as G♯7♯9

DegreeIntervalSemitonesNoteHear
1Root0A♭(Ab)
3Major third4C
5Perfect fifth7E♭(Eb)
♭7Minor seventh10G♭(Gb)
♯9Augmented ninth15B

How to use the A♭7♯9 chord

The A♭7♯9 chord is built from a root, a major third, a perfect fifth, a minor seventh and an augmented ninth. Start at the root A♭ and stack the intervals to get the whole chord: A♭, C, E♭, G♭ and B. The same formula gives you the chord in any other key.

Dominant seventh sharp nine chords drive funk, blues-rock and fusion as the tonic of a dominant-based vamp, not only as a V chord. Whole grooves in soul and rock guitar are built around this one chord.

How A♭7♯9 differs from similar chords

A♭7♯9 holds both a major third and a raised ninth that sounds like a minor third, so it is major and minor at once. That clash separates it from A♭7♭9, where the ninth is lowered, and from A♭9, where it is natural. Guitarists often call it the Hendrix chord.

Where A♭7♯9 is used

A dominant chord wants to resolve. Its home is the V of a major key - and the I of a blues, where the pull never lets up.

As the VD♭ major
  1. ii7E♭m7
  2. V7♯9A♭7♯9
  3. Imaj7D♭maj7

A♭7♯9 is the chord that wants to resolve, so ending the loop on it hands straight back to the top.

Questions people ask

What notes are in the A♭7♯9 chord?
The A♭7♯9 chord contains A♭, C, E♭, G♭ and B (Ab, C, Eb, Gb and B in plain text).
Is the A♭7♯9 chord major or minor?
A♭7♯9 is a altered dominant seventh chord. Dominant seventh sharp nine chords sound gritty and bluesy at once, the clash of a major third against a sharp ninth that reads to the ear like a minor third. Funk, rock and soul horn sections lean hard on this one chord.
How do you play A♭7♯9 on piano?
Place your fingers on A♭, C, E♭, G♭ and B and play them together. The root usually goes to the little finger of the left hand, the upper notes to the right. On the keyboard A♭, E♭ and G♭ are black keys and C and B are white. The thumb starts on a black key, so slide the whole hand a little further in, towards the fallboard.
How do you play A♭7♯9 on guitar?
Use the fingering in the diagram above. This one is a barre at fret 1: keep the index finger flat across the strings and curve the others so they don't mute the strings next to them. String 2 rings open.
What is another name for the A♭7♯9 chord?
A♭7♯9 is enharmonically equivalent to G♯7♯9. Both chord names describe exactly the same notes, but the spelling depends on the key you are playing in.