A9 Guitar Chord

A9 is the A dominant ninth chord. It has five notes: A, C sharp, E, G and B. The shape on this page needs only two fingers, because the open A, B and high E strings already supply three of the five notes.

5fr12×AGC♯BE

Two fingers on the D and G strings at the 5th and 6th frets, with the open A, B and high E strings filling in the root, ninth and fifth.

How to play A9, step by step

  1. Index finger: 5th fret, D string
  2. Middle finger: 6th fret, G string
  3. Leave the A and B and high E strings open. Strum from the A string down, skipping the low E.

This shape is one of a family: keep the two fingers on the D and G strings and move them together. At the 5th fret both, it is Am9; at the 6th fret both, Amaj9.

More ways to play A9

There are 2 common A9 shapes in total: the standard one at the top of the page, plus these, easiest first. You only ever need one. Tap any card to hear it.

Barre at fret 5
A9 guitar chord diagram, barre at fret 5, played 5x5657

Full and low, with the ninth ringing on the top string over a heavy root. This is the shape that sounds like a horn section.

If it sounds uneven

One of the two fretted notes buzzes
They sit at the 5th and 6th frets on the D and G strings. Both need fingertip pressure right behind the fret; a lazy 6th fret makes the chord sound like something else.
The open strings drown the fretted ones
Three open strings ring for a long time. Pick or strum slightly toward the middle strings so the third and seventh come through.
The low E rings
It is not in the chord. Strum from the open A string down so A stays the lowest note.

What makes it an A9

A · C♯ · E · G · B 1 3 5 ♭7 9

A9 is an A7 chord with a ninth added: A, C sharp, E and G make the seventh chord, and the B on top is the ninth. In this shape the open A gives the root, the open B the ninth, and the open high E the fifth.

Its job is the V chord of D, and it is the I chord of a blues in A. The ninth keeps the dominant pull of A7 while adding a smoother, more modern colour.

A9 vs A7

A9 adds a B to A7. Both push toward D, but A7 sounds gritty and A9 sounds polished.

In a blues in A, A7 fits a raw shuffle and A9 fits a funk or soul groove. Many players use both in the same song for exactly that contrast.

A9 chord questions

Is A9 hard to play?

No. This shape is two fingers on the D and G strings with three open strings around them, which makes it one of the easiest ninth chords on the guitar.

What is the difference between A9 and Aadd9?

A9 contains a G, the flat seventh, and behaves like a blues or funk chord. Aadd9 has no seventh at all and sounds like a bright A major with an extra note.

How does A9 relate to Am9 and Amaj9?

All three use the same two finger pattern on the D and G strings with the same open strings. A9 is the 5th and 6th frets, Am9 is the 5th and 5th, Amaj9 is the 6th and 6th. Learning one gives you all three.

Where is A9 used?

As the V chord in D, as the I chord of a blues in A, and in funk and soul, where ninths replace plain sevenths.

Do you strum the low E?

No. Start on the open A so the root is the lowest note in the chord.

Chords to learn next

Other A chords