A7 A dominant seventh chord
- Notes
- A C# E G
- Formula
- 1 3 5 b7
- Semitones
- 0 4 7 10 above the root
- Other symbols
- Adom7
A to C# is a major third (4 semitones), C# to E is a minor third (3 semitones), E to G is a minor third (3 semitones). A dominant seventh is a major triad plus a minor seventh (G, 10 semitones above A). It is the V chord that leads back home, and the basic chord of the blues.
A7 on the piano
Root position from A4: A4, C#5, E5, G5. Middle C is C4.
A7 on the guitar
Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has A as its lowest note.
x 0 2 0 2 0 (low E to high e)
Sounds A2 E3 G3 C#4 E4
5 7 5 6 5 5 (low E to high e)
Sounds A2 E3 G3 C#4 E4 A4
The barre shapes are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play dominant seventh chords on other roots.
Inversions of A7
An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.
| Position | Notes, bass first | Named | Listen |
|---|---|---|---|
| Root position | A C# E G | A7 | |
| 1st inversion | C# E G A | A7/C# | |
| 2nd inversion | E G A C# | A7/E | |
| 3rd inversion | G A C# E | A7/G |
Where A7 fits
A7 is V7 in D major, V7 in D minor. Its C# and G are a tritone apart (6 semitones). In D major the C# usually rises a half step to D and the G falls a half step, which is why A7 pulls so strongly towards D.