Aadd9
A Added 9th — a plain triad plus the ninth — colour without the seventh, clean and contemporary.
The keys
A – C♯ – E – B
What's inside Aadd9
| Note | Interval from root | Degree |
|---|---|---|
| A | Root | 1 |
| C♯ | Major 3rd | 3 |
| E | Perfect 5th | 5 |
| B | Major 9th | 9 |
Inversions
| Position | Keys (low → high) |
|---|---|
| Root position | A4 – D♭5 – E5 – B5 |
| 1st inversion | D♭5 – E5 – B5 – A5 |
| 2nd inversion | E5 – B5 – A5 – D♭6 |
| 3rd inversion | B5 – A5 – D♭6 – E6 |
A working voicing
Split the chord between two hands the way working players do — a solid shell low down, the colour tones up top:
| Hand | Keys |
|---|---|
| Left (shell) | A2 – E3 |
| Right (colour) | D♭5 – B5 |
Where Aadd9 lives
As the I chord
Aadd9 → D → E → Aadd9
The classic I–IV–V–I motion with this chord as home.
In a ii–V–I
Bm7 → E7 → Aadd9
The strongest cadence in harmony, resolving onto this chord.
Put Aadd9 under your fingers
Hear every voicing, see the keys light up, and drill it in the interactive Chord & Voicing Lab.
Open the Chord & Voicing Lab →