4 notes · 1 · 3 · 5 · ♭7

A Dominant Seventh Piano Chord (A7)

A7 is built from A, C#, E and G — the formula 1 · 3 · 5 · ♭7, or 4, 7 and 10 semitones above A. The shape uses 3 white and 1 black key, and you can hear it, invert it and compare it below.

Root noteChord type

Chord

A Dominant seventh

Notes

A · C# · E · G

Formula

1 · 3 · 5 · ♭7

Right hand

1 · 2 · 3 · 5

Choose a chord, then play it. Finger numbers run from thumb (1) to little finger (5).

The finder above already holds A7. Press P or the Play chord button to hear A, C#, E, G sounded together, then change the root or the chord type to compare it with something else.

Chord tones

The notes in A7

A dominant seventh chord is a major triad with a minor seventh added on top. The tritone between its third and its seventh is unstable and pulls strongly towards the chord a fifth below, which is what makes it the engine of blues, gospel and most cadences. In a major key it is built on the fifth degree.

Each tone of A dominant seventh with its interval, scale degree, distance in semitones from A and a suggested right-hand finger.
Note	Interval	Degree	Semitones	Right hand
Awhite key	Root	1	0	1 · thumb
C#black key	Major third	3	4	2 · index finger
Ewhite key	Perfect fifth	5	7	3 · middle finger
Gwhite key	Minor seventh	♭7	10	5 · little finger

Step by step

How to play A7 on piano

Find A: it is the white key between the second and third black keys of a group of three.
Build upwards from A using 4, 7 and 10 semitones to reach C#, E and G.
With the right hand, place finger 1 on A, finger 2 on C#, finger 3 on E and finger 5 on G. Keep the wrist level and the knuckles rounded.
Move your hand a little further in towards the fallboard so the black key sits comfortably under your fingers.
Play the notes together, then one at a time from the bottom up, and listen to how A7 settles.
Try first inversion as well: C# – E – G – A. Inversions let you change chords without jumping around the keyboard.

Inversions

A7 in 4 positions

An inversion keeps the same 4 notes and simply moves the lowest one up an octave. Learning them means you can change chords with small hand movements instead of jumping to a new part of the keyboard.

Root position

A – C# – E – G

The root A is the lowest note. This is the shape most people learn first.

First inversion

C# – E – G – A

C# is the lowest note, so the major third sits in the bass and the notes below it move up an octave.

Second inversion

E – G – A – C#

E is the lowest note, so the perfect fifth sits in the bass and the notes below it move up an octave.

Third inversion

G – A – C# – E

G is the lowest note, so the minor seventh sits in the bass and the notes below it move up an octave.

In context

Which keys contain A7

In D major the chord functions as V7. Altogether it is produced by the scales of 3 keys, so learning it once pays off in several places.

D majorV7
D harmonic minorV7
B minorVII7

Chord tones are spelled by the degree they occupy, so the third of a minor chord is written as a flat rather than a sharp even though it is the same key on the piano. A double sharp such as F## means the key one whole tone above F.

Compare

A7 against Amaj7

A7 and Amaj7 share A, C# and E. Moving the major seventh G# down 1 semitone to the minor seventh G turns Amaj7 into A7.

Practise the pair together: hold the shared notes A, C#, E still and move only the one finger. Hearing that single change is the quickest way to recognise the two chords by ear.

Open Amaj7 →

Good questions

A7 questions

What notes are in the A7 chord?

A7 contains A, C#, E and G. Counted from the root, that is the formula 1 · 3 · 5 · ♭7, or 4, 7 and 10 semitones above A.

What is the right-hand fingering for A7?

A comfortable beginner fingering is 1 (thumb) on A, 2 (index finger) on C#, 3 (middle finger) on E and 5 (little finger) on G. Finger numbers run from the thumb (1) to the little finger (5), and they change once you start using inversions.

How is A7 different from Amaj7?

A7 and Amaj7 share A, C# and E. Moving the major seventh G# down 1 semitone to the minor seventh G turns Amaj7 into A7.

Which keys use the A7 chord?

It occurs naturally in D major (V7), D harmonic minor (V7) and B minor (VII7). The roman numeral shows which degree of the key the chord is built on.

What are the inversions of A7?

root position is A – C# – E – G, first inversion is C# – E – G – A, second inversion is E – G – A – C# and third inversion is G – A – C# – E. Every inversion holds the same notes; only the lowest one changes.