Amaj9 A major ninth chord
- Notes
- A C# E G# B
- Formula
- 1 3 5 7 9
- Semitones
- 0 4 7 11 14 above the root
- Other symbols
- AM9, AΔ9
A to C# is a major third (4 semitones), C# to E is a minor third (3 semitones), E to G# is a major third (4 semitones), G# to B is a minor third (3 semitones). A major seventh (Amaj7) with the ninth, B, on top. The fifth, E, is often left out on guitar.
Amaj9 on the piano
Root position from A4: A4, C#5, E5, G#5, B5. Middle C is C4.
Amaj9 on the guitar
Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has A as its lowest note.
5 4 6 4 5 x (low E to high e)
Sounds A2 C#3 G#3 B3 E4
x 12 11 13 12 x (low E to high e)
Sounds A3 C#4 G#4 B4, fifth left out
The E-shape and A-shape grips are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play major ninth chords on other roots.
Inversions of Amaj9
An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.
| Position | Notes, bass first | Named | Listen |
|---|---|---|---|
| Root position | A C# E G# B | Amaj9 | |
| 1st inversion | C# E G# B A | Amaj9/C# | |
| 2nd inversion | E G# B A C# | Amaj9/E | |
| 3rd inversion | G# B A C# E | Amaj9/G# | |
| 4th inversion | B A C# E G# | Amaj9/B |
Where Amaj9 fits
Amaj9 is Imaj9 in A major, IVmaj9 in E major. Its upper four notes C# E G# B are C#m7: play that chord over a A bass and you have Amaj9.