FMFretboardMentor
PL

A9 Chord on Guitar

A9 is the A dominant 9th chord — 5 notes (A, C♯, E, G, B) built from the formula 1 3 5 ♭7 9. Below are playable shapes across the fretboard, the keys it belongs to and the scales to use when soloing over it.

Notes: A · C♯ · E · G · BFormula: 1 · 3 · 5 · ♭7 · 9Hear it and see it on the fretboard ▸

A9: Chord shapes (open & barre)

  • A9 – open position×R593♭7open position
  • A9 – fret 2R95R3♭7fret 2
  • A9 – fret 4R3♭795×fret 4
  • A9 – fret 55R5♭7359fret 5
  • A9 – fret 66××R3♭79fret 6
  • A9 – fret 99×R9♭7R3fret 9
  • A9 – fret 1111×R3♭79×fret 11

A9: Shell voicings (jazz)

  • A9 – R-3-7R3♭7×××R-3-7
  • A9 – R-3-711×R3♭7××R-3-7
  • A9 – R-7-35R×♭73××R-7-3
  • A9 – R-7-312×R×♭73×R-7-3

Keys that contain A9

Scales to play over A9

Ordered from the most common choice. All of them contain A, C♯, E, G, B.

Other A chords

Triads

Sevenths

Sixths

Added

Extended

Dominant 9th chords in other keys

FAQ

What notes are in the A9 chord?
A9 (A dominant 9th) contains A, C♯, E, G, B — formula 1 3 5 ♭7 9.
How do you play A9 on guitar?
A common shape is x02423 (low E to high E, x = muted string, open position). This page shows more shapes, drop 2, drop 3 and shell voicings in the interactive library.
What scale goes with A9?
Good choices to solo over A9: A Mixolydian, A Lydian dominant, A Mixolydian ♭6.
What key is A9 in?
A9 is diatonic in D major (V9), B minor (♭VII9).