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A9 chord

A dominant 9th

C4
A
C5
C#
E
G
B

Want it in context? Open A9 on the full piano.

Notes

  • A
    R
  • C#
    3
  • E
    5
  • G
    b7
  • B
    9

Formula: R – 3 – 5 – b7 – 9

A9 inversions

The same notes, with a different note in the bass.

Root position A9

C4
A
C5
C#
E
G

1st inversion A9/C#

C5
C#
E
G
A
C6

2nd inversion A9/E

C5
E
G
A
C6
C#

3rd inversion A9/G

C5
G
A
C6
C#
E

More A chords

Dominant 9th chords in other keys

FAQ

What notes are in the A9 chord?

The A dominant 9th chord (A9) has 5 notes: A, C#, E, G and B.

How do you play A9 on the piano?

Put your right hand on A, C#, E, G and B, starting from A. A common fingering for three-note chords is thumb (1), middle finger (3) and little finger (5).

What is the formula of a dominant 9th chord?

R – 3 – 5 – b7 – 9 (in semitones from the root: 0, 4, 7, 10, 14).