A7♭9 Chord: Guitar, Piano and Notes

The A7♭9 chord is a altered dominant seventh chord built on the root note A. Its notes are A, C♯, E, G and B♭.

Transpose
Quality
Short answer

Dominant seventh flat nine chords sound dark and urgent. Stacking a minor ninth on a dominant seventh tightens the tension already built into the tritone, which makes the chord a strong pull toward a minor tonic.

Notes
A · C♯ · E · G · B♭
Formula
1 · 3 · 5 · ♭7 · ♭9
Semitones
0 · 4 · 7 · 10 · 13
Note
A
Quality
Dominant 7♭9
Symbol
A7♭9

A7♭9 on piano

5 notes
View:
Piano diagram of the A7♭9 chord

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

To play A7♭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. Practice moving in and out of the chord slowly, then bring in a metronome.

  • A1
  • C♯3
  • E5
  • G♭7
  • B♭♭9

A7♭9 on guitar

View:
Guitar chord diagram of the A7♭9 chord

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

On guitar, A7♭9 is commonly played with the voicing shown above. Strum only the strings marked as active in the diagram.

A7♭9 chord notes

DegreeIntervalSemitonesNoteHear
1Root0A
3Major third4C♯(C#)
5Perfect fifth7E
♭7Minor seventh10G
♭9Minor ninth13B♭(Bb)

How to use the A7♭9 chord

The A7♭9 chord is built from a root, a major third, a perfect fifth, a minor seventh and a minor 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 flat nine chords are the classic altered dominant of bebop and gospel, most often the V7 of a ii-V-i in a minor key. Gospel piano voices this chord thick under the vocal line right before it resolves.

Where A7♭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. ii7Em7
  2. V7♭9A7♭9
  3. Imaj7Dmaj7

A7♭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 A7♭9 chord?
The A7♭9 chord contains A, C♯, E, G and B♭ (A, C#, E, G and Bb in plain text).
Is the A7♭9 chord major or minor?
A7♭9 is a altered dominant seventh chord. Dominant seventh flat nine chords sound dark and urgent. Stacking a minor ninth on a dominant seventh tightens the tension already built into the tritone, which makes the chord a strong pull toward a minor tonic.
How do you play A7♭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.
How do you play A7♭9 on guitar?
A7♭9 is typically played with the fingering shown in the diagram above. If one of the chord tones lines up with an open string, an open position is worth trying too.
What chords work well with A7♭9?
A7♭9 pairs naturally with the chords in the related section: a perfect fifth up or down, the relative major or minor, and anything sharing two notes with it.