A major ninth
How to play Amaj9 — Major ninth
Amaj9 (Major ninth)A · C♯ · E · G♯ · B
Guitar samples: Acoustic guitar — University of Iowa (via tonejs-instruments, CC-BY 3.0)
A major ninth — notes and structure
The Amaj9 chord is a major seventh chord with the ninth added — rich and dreamy.
The Amaj9 major ninth consists of the notes A, C♯, E, G♯, B. Its interval structure is R–3–5–7–9 — the root, then each chord tone stacked above it. This is the same chord you see in the interactive finder above, drawn on the guitar fretboard with the root circled and every chord tone labelled.
Amaj9 stacks a major third (C♯), a perfect fifth (E), a major seventh (G♯) and a ninth (B) above the root A.
The finder shows 2 ways to play Amaj9 — an open-position shape reaching up to the 9th fret. 1 of them use a barre.
What key is Amaj9 in?
Every note of Amaj9 belongs to the scales below, so the chord sounds at home in each of these keys — the roman numeral is the degree it sits on.
- A major — the I chord
- E major — the IV chord
- F♯ minor — the III chord
- C♯ minor — the VI chord
Chords that go with Amaj9
In A major, the chords built on the first, fourth and fifth degrees carry most songs — put Amaj9 next to these:
Frequently asked questions
- What notes are in the A major ninth chord?
- The Amaj9 chord contains the notes A, C♯, E, G♯, B. It is a major seventh chord with the ninth added — rich and dreamy.
- How many ways can you play Amaj9 on guitar?
- 2 voicings are shown on this page — from open position up the neck — each with its own fingering diagram and audio.
- Is Amaj9 a hard chord to play?
- Some voicings use a barre, which takes practice, but the chord is very playable once that shape is comfortable.
- What key does Amaj9 belong to?
- Amaj9 fits A major (where it is the I chord), E major (where it is the IV chord), F♯ minor (where it is the III chord) — every note of the chord is in those scales.