A7
A Dominant 7th — the engine of harmonic motion — the tritone between its third and seventh drives resolution down a fifth.
The keys
A – C♯ – E – G
What's inside A7
| Note | Interval from root | Degree |
|---|---|---|
| A | Root | 1 |
| C♯ | Major 3rd | 3 |
| E | Perfect 5th | 5 |
| G | Minor 7th | b7 |
Inversions
| Position | Keys (low → high) |
|---|---|
| Root position | A4 – D♭5 – E5 – G5 |
| 1st inversion | D♭5 – E5 – G5 – A5 |
| 2nd inversion | E5 – G5 – A5 – D♭6 |
| 3rd inversion | G5 – 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 – G3 |
| Right (colour) | D♭5 – E5 |
Where A7 lives
Resolving down a fifth
A7 → D
The defining dominant move: the tritone inside this chord releases onto the chord a fifth below.
In a ii–V–I
Em7 → A7 → Dmaj7
This chord as the V — the engine of the most-used cadence in music.
Put A7 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 →