Chord · 9ths
A9 — A Dominant 9th
A9 is the A dominant 9th chord. It is built on the root A with major 3rd (C♯), perfect 5th (E), minor 7th (G) and major 9th (B) above it — the formula 1 3 5 ♭7 9, sounding the notes A C♯ E G B. On the piano it sits at A (octave 3) and above in the library's voicing; the same 5 notes in any octave are still A9.
- Root
- A
- Quality
- Dominant 9th
- Formula
- 1 3 5 ♭7 9
- Notes
- A C♯ E G B
On the keyboard
Right-hand fingering for this voicing: 1–2–3–4–5 (1 is the thumb).
The notes of A9
| Degree | Note | Interval from the root | Pitch |
|---|---|---|---|
| 1 | A | root | A3 |
| 3 | C♯ | major 3rd | C♯4 |
| 5 | E | perfect 5th | E4 |
| ♭7 | G | minor 7th | G4 |
| 9 | B | major 9th | B4 |
Other 9ths on A
Dominant 9th chords on every root
Part of the chord reference. See also the scales and the keys.