A dominant ninth (A9) chord on guitar

The A dominant ninth chord (A9) is a dominant ninth chord (a dominant seventh plus a major ninth), made of five notes: A – C♯ – E – G – B.

Dots show:

Open positionmedium

Position 2medium

E shape, fret 5hard

Position 6medium

C shape, fret 11medium

Tap a string on a diagram to hear just that string. The sound is generated in your browser with a physical string model.

Chord finder Transposer Tuner

What the A9 chord sounds like

A dominant ninth is a dominant seventh with an added major ninth. A fuller, fatter dominant sound – a staple of funk, soul and blues.

Notes of the A9 chord

Degree	Note	Interval from the root
1	A	root
3	C♯	major third (4 semitones)
5	E	perfect fifth (7 semitones) – often omitted on fretted instruments
7	G	minor seventh (10 semitones)
9	B	major second (2 semitones)

How to play it – with fingering

Open position

String 1 (e): fret 3, little finger (G4)
String 2 (B): fret 2, middle finger (C♯4)
String 3 (G): fret 4, ring finger (B3)
String 4 (D): fret 2, index finger (E3)
String 5 (A): open (A2)
String 6 (E): not played

Position 2

String 1 (e): open (E4)
String 2 (B): open (B3)
String 3 (G): open (G3)
String 4 (D): fret 2, index finger (E3)
String 5 (A): fret 4, ring finger (C♯3)
String 6 (E): fret 5, little finger (A2)

E shape, fret 5, barre at fret 5

String 1 (e): fret 7, little finger (B4)
String 2 (B): fret 5, index finger (E4)
String 3 (G): fret 6, middle finger (C♯4)
String 4 (D): fret 5, index finger (G3)
String 5 (A): fret 7, ring finger (E3)
String 6 (E): fret 5, index finger (A2)

For the barre, lay your index finger flat across all the marked strings at fret 5; your other fingers press the higher frets.

The “C, A, G, E and D shapes” are the CAGED system: you slide the shape of the open C, A, G, E or D chord up the neck and your index finger (a barre) takes over the job of the nut. That way the same chord can be played in five places, anywhere on the fretboard.

Tuning: E A D G B E (low to high). String 6 is the thickest, the low E. In the diagram, × means the string is not played, and a circle means an open string.

Playing A9 with a capo

A capo clamps all the strings at one fret, so a familiar open shape sounds higher. You can also get a A9 chord with these open shapes:

Capo: fret 5
shape: E9

Rework a whole song for a capo: chord transposer →

Which keys is it in?

The A9 chord is built from the notes of these keys (for minor keys, both the natural and the harmonic minor are considered):

D major: V9 (dominant)
B minor: VII9

Similar chords and substitutes

If A9 is too hard, or you want a different colour in the same spot, these chords are worth a try.

Substitutes (by function)

E♭7 – tritone substitute: the same third and seventh, swapped – a jazz favourite
C♯dim7 – diminished seventh on the third: a common stand-in for the dominant
A7 – a simpler dominant
A7sus4 – suspended dominant, less tense
D – where it resolves (V → I)

Simpler versions

A7 – all 4 of its notes are in this chord
Aadd9 – all 4 of its notes are in this chord
A – all 3 of its notes are in this chord
Asus2 – all 3 of its notes are in this chord

Richer versions

A11 – the same chord plus 1 colour note
A13 – the same chord plus 1 colour note

Frequently asked questions

What notes are in the A9 chord?

A, C♯, E, G, B. The root is A; the intervals of the other notes from the root: major third, perfect fifth, minor seventh, major second.

What is the easiest way to play A9 on guitar?

The easiest shape above is “Open position”. We show 5 shapes, from open and easy versions to movable barre shapes higher up the neck. With a capo you can also play it as a E9 shape at fret 5.

How do I read the chord diagram?

Strings run from the lowest (left) to the highest (right) – tick “Left-handed” to mirror it. Rows are frets; a number at the side shows the starting fret. Dots are fingers (1 index, 2 middle, 3 ring, 4 little), a long bar is a barre, × means don't play that string and ○ means play it open.

Why is a note missing from some A9 shapes?

On a fretted instrument you can't always play every note of a 5-note chord. The fifth (E) may be dropped – the chord keeps its character without it.

How is the A9 chord written?

The chord symbol is A9, and its full name is A dominant ninth.