A Dominant 7th Chord (A7) on Piano
The A7 chord (A dominant 7th) is built from 4 notes: A – C# – E – G.
Play these notes on a MIDI keyboard, your computer keyboard, or the on-screen keys and ChordKeys will name the chord back to you.
Notes and intervals
| Note | Degree | Interval from A | Semitones |
|---|---|---|---|
| A | 1 | root | 0 |
| C# | 3 | major 3rd | 4 |
| E | 5 | perfect 5th | 7 |
| G | b7 | minor 7th | 10 |
Inversions
Rearranging which note sits at the bottom gives you 4 playable voicings of the same chord. Inversions let you move between chords with less hand movement.
| Voicing | Notes | Bass note |
|---|---|---|
| Root position | A – C# – E – G | A in the bass |
| 1st inversion | C# – E – G – A | C# in the bass |
| 2nd inversion | E – G – A – C# | E in the bass |
| 3rd inversion | G – A – C# – E | G in the bass |
How the dominant 7th chord is built
Every dominant 7th chord uses the same interval formula: 1 (0 semitones), 3 (4 semitones), 5 (7 semitones), b7 (10 semitones). Starting on A and applying that formula produces A, C#, E, G. Learn the formula once and you can build a dominant 7th chord on any of the twelve roots.
Keys that contain A7
Every note of A7 belongs to these keys, so it will sit naturally in a progression written in any of them.
Other chords on A
Dominant 7th chords on other roots
Frequently asked questions
What notes are in a A7 chord?
A A7 chord contains the notes A, C#, E, G. Those are the 1, 3, 5, b7 degrees measured from the root note A.
How do you play A7 on piano?
Place your thumb on A, then add C# and E and G above it. With a right hand in root position the common fingering is 1–2–3–5.