A ninth, suspended fourth
How to play A9sus4 — Ninth, suspended fourth
A9sus4 (Ninth, suspended fourth)A · D · E · G · B
Guitar samples: Acoustic guitar — University of Iowa (via tonejs-instruments, CC-BY 3.0)
A ninth, suspended fourth — notes and structure
The A9sus4 chord is a ninth chord with the third suspended — soulful and open.
The A9sus4 ninth, suspended fourth consists of the notes A, D, E, G, B. Its interval structure is R–4–5–7–9 — 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.
A9sus4 stacks a perfect fourth (D), a perfect fifth (E), a minor seventh (G) and a ninth (B) above the root A.
The finder shows 2 ways to play A9sus4 — an open-position shape reaching up to the 5th fret. None of them need a barre.
What key is A9sus4 in?
Every note of A9sus4 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.
- C major — the VI chord
- G major — the II chord
- D major — the V chord
- A minor — the I chord
Chords that go with A9sus4
In C major, the chords built on the first, fourth and fifth degrees carry most songs — put A9sus4 next to these:
Frequently asked questions
- What notes are in the A ninth, suspended fourth chord?
- The A9sus4 chord contains the notes A, D, E, G, B. It is a ninth chord with the third suspended — soulful and open.
- How many ways can you play A9sus4 on guitar?
- 2 voicings are shown on this page — from open position up the neck — each with its own fingering diagram and audio.
- Is A9sus4 a hard chord to play?
- It is fairly beginner-friendly — there is an open-position shape and none of the voicings need a barre.
- What key does A9sus4 belong to?
- A9sus4 fits C major (where it is the VI chord), G major (where it is the II chord), D major (where it is the V chord) — every note of the chord is in those scales.