root position: A9
A – C♯ – E – G – B
A9 Piano Chord
The A dominant 9 chord (A9) is made of the notes A, C♯, E, G and B. Its formula is 1 – 3 – 5 – ♭7 – 9.
Notes in A9
| Note | Formula | Interval from root |
|---|---|---|
| A | 1 | root |
| C♯ | 3 | major 3rd |
| E | 5 | perfect 5th |
| G | ♭7 | minor 7th |
| B | 9 | major 9th |
How to play A9 on piano
- Right hand: fingers 1-2-3-4-5
- Left hand: fingers 5-4-3-2-1
Fingers are numbered from the thumb (1) to the little finger (5).
This chord spans more than an octave. Many players leave out the 5th, or play the root in the left hand and the other notes in the right.
A9 inversions
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
Other names for A9
A9 is also written as Adom9.
Keys that contain A9
A9 is not one of the basic chords of any major or minor key. It is usually used as a passing or colour chord.