A ninth chord (A9) on piano

The A ninth chord (A9) on piano has 5 notes: A, C sharp, E, G, and B (A, C♯, E, G, B). With the right hand, use fingers 1-2-3-4-5; with the left hand, 5-4-3-2-1 (1 is the thumb). On the keyboard below, the root (A) has the strongest color; each key shows the note name and the degree.

Notes: AC♯EGB
Formula: 135♭79

How to play A9 on piano

Root position · From low to high: A C♯ E G B

A9 chord (A ninth) on piano, root position: keys A, C#, E, G, B

Right hand: 1-2-3-4-5 Left hand: 5-4-3-2-1

Fingers: 1 = thumb, 2 = index, 3 = middle, 4 = ring, 5 = little finger. The small dot marks middle C (C4). Tap a key to hear the note.

A9 chord inversions

Inverting a chord means putting another of its notes in the bass (the lowest key) without changing the notes. Inversions shorten the way your hand travels from one chord to the next and slightly change the color of the sound.

1st inversion (A9/C#)

A9/C#: C sharp (3) in the bass

From low to high: C♯ E G A B
2nd inversion (A9/E)

A9/E: E (5) in the bass

From low to high: E G A B C♯
3rd inversion (A9/G)

A9/G: G (♭7) in the bass

From low to high: G A B C♯ E

Notes and intervals of A9

A9 (A ninth) is built from 5 notes. Each one fills a degree of the chord:

A · 1 · root
C♯ · 3 · major third
E · 5 · perfect fifth
G · ♭7 · minor seventh
B · 9 · ninth

About the ninth chord

A dominant chord with a ninth: the seventh plus the ninth make the chord full and groovy. It is the sound of funk, soul, samba-jazz and modern blues, and it can almost always stand in for a plain seventh chord.

Other A chords

Ninth: other roots

Frequently asked questions

What are the notes of the A9 chord on piano?

A9 (A ninth) has the notes A, C♯, E, G, B. The formula is 1 · 3 · 5 · ♭7 · 9: root, major third, perfect fifth, minor seventh, ninth.

How do you play A9 on piano?

Find the A key and add the other notes above it: A, C♯, E, G, B. Play them all together. With the right hand, use fingers 1-2-3-4-5; with the left hand, 5-4-3-2-1.

What are the inversions of A9?

1st inversion (A9/C#): C♯ E G A B; 2nd inversion (A9/E): E G A B C♯; 3rd inversion (A9/G): G A B C♯ E.

What does A9 mean?

A9 is the chord symbol for A ninth. A dominant chord with a ninth: the seventh plus the ninth make the chord full and groovy. It is the sound of funk, soul, samba-jazz and modern blues, and it can almost always stand in for a plain seventh chord.

Is the A9 chord the same on piano and keyboard?

Yes. The notes and inversions are the same on any keyboard instrument: acoustic piano, digital piano, keyboard, organ or synthesizer.

A9 on other instruments

All piano chords