A dominant ninth piano chord - A9

The A dominant ninth chord is a 5-note chord consisting of the notes A, C#, E, G and B.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as A9.

Interactive piano diagram for the A dominant ninth chord

Piano keyboard displaying the A dominant ninth chord with the notes AFbEGCbBC#Db

Extended Chords

Chords that are a superset of A9. The chords include more notes but always A, C#, E, G and B.

Reduced chords

Chords that are a subset of A9. These contain less notes but all of them are included in A9.

Scales with A9

Below you find all scales that include A9:

  • bebop
  • mixolydian
  • mixolydian b6
  • lydian dominant
  • lydian minor
  • bebop minor
  • composite blues
  • messiaen's mode #3
  • chromatic

A dominant ninth piano chord chart image

In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the A9 chord. Feel free to save or share the image as needed.

Piano chord chart for the A dominant ninth chord (A9). The notes A, C#, E, G and B are highlighted.