Skip to main content

A7(Dominant 7th Chord)

A major triad with a minor seventh. Creates harmonic tension that resolves to the tonic.

Notes
A – C# – E – G
Intervals (semitones)
0 – 4 – 7 – 10
Type
7th Chord

🎹 A7 on Piano

Press highlighted keys simultaneously to play the A7 chord.

R
A(Root (R))
2
C#(Major 3rd)
3
E(Perfect 5th)
4
G(Minor 7th (♭7))

🎸 A7 on Guitar

The A7 chord uses notes A, C#, E, G. Build a voicing by finding these notes on any strings — root on the 6th string is a common starting point for barre chord shapes.

Interval Analysis

DegreeInterval NameSemitonesNote in A
RootRoot (R)0A
3rdMajor 3rd4C#
5thPerfect 5th7E
7thMinor 7th (♭7)10G

About the A Dominant 7th Chord

The A7 chord (A Dominant 7th) consists of 4 notes: A, C#, E, G. A major triad with a minor seventh. Creates harmonic tension that resolves to the tonic.

To build any dominant 7th chord, apply intervals of 0, 4, 7, 10 semitones above the root. Starting from A: the notes land on A, C#, E, G.

Playing A7 on Piano

Press A, C#, E, G simultaneously. In root position, A is lowest. First inversion places C# in the bass for a lighter sound; second inversion uses E as the bass note.

Common Chord Progressions Using A7

  • I–IV–V: A7 – D7 – E7 (blues and rock)
  • I–V–vi–IV: A7 – E – F#m – D (pop staple)
  • I–vi–IV–V: A7 – F#m – D – E (50s progression)

The A7 Chord in Context

As a dominant 7th chord, A7 is the tonic (I) in the key of A major. It also appears as the IV chord in E major, and as the V chord in D major — making it one of the most important chords across all of Western music.

Other A Chords

A
Major
Am
Minor
Amaj7
Major 7th
Am7
Minor 7th
Adim
Diminished
Aaug
Augmented

Dominant 7th Chord in All 12 Keys

C7C#7D7D#7E7F7F#7G7G#7A7A#7B7
🎹 Virtual Piano
Play A7 on piano
🎸 Virtual Guitar
See on the fretboard
🎵 A Scale
Notes that fit A7
🎶 Songs
Find songs using A7

FAQ

A7 Chord — Frequently Asked Questions

What notes are in the A7 chord?
The A Dominant 7th chord contains: A, C#, E, G. These notes are derived by applying the dominant 7th interval formula (0–4–7–10 semitones) to the root note A.
What is the A7 chord used for?
A major triad with a minor seventh. Creates harmonic tension that resolves to the tonic. The A7 chord is used across pop, rock, jazz, and classical music. As the I chord in the key of A major, it functions as the most stable resting point in progressions.
How do you play A7 on piano?
On piano, play A, C#, E, G simultaneously. In root position, A is the lowest note. Inversions move the bass note up — first inversion has C# lowest, second inversion has E lowest.
How many notes are in a dominant 7th chord?
A dominant 7th chord has 4 notes: A, C#, E, G (in A). It is a 7th chord, extending beyond the basic triad.
What is the difference between A major and A minor?
The A major chord (A–C#–E) uses a major third (4 semitones), giving it a bright, happy sound. The A minor chord (A–C–E) uses a minor third (3 semitones), giving it a darker, emotional sound.
What key does A7 belong to?
A7 naturally serves as the I chord in the key of A major. It also appears as IV in the key of E major, and as V in the key of D major.
Can I play A7 on ukulele?
Yes. The ukulele uses GCEA tuning with 4 strings. The A7 chord notes (A, C#, E, G) can be fretted on a ukulele, though the shapes differ from guitar due to the 4-string layout and shorter scale.
What chords go well with A7?
In the key of A major, A7 pairs naturally with D major (IV), E major (V), and F#m (vi). The classic I–IV–V (A7–D–E) is the foundation of blues, country, and rock.
What is a chord inversion of A7?
An inversion places a non-root note in the bass. A7 root position: A in bass. First inversion: C# in bass. Second inversion: E in bass. Inversions create smoother bass line movement without changing the harmony.
How do I memorize the notes in a dominant 7th chord?
Remember the formula: 0–4–7–10 semitones from root. For A7: start on A, add 4 semitones, then 7 semitones, then 10 semitones. Practicing this across all 12 roots builds instant recognition of any dominant 7th chord.