A7

Q: What notes are in the A7 chord?

The A7 chord (A Dominant 7) contains: A, C#, E, G. Its interval structure is shown above in the Theory section.

Q: How do I build A7 on the keyboard?

Take the root and add the remaining chord tones following the interval formula. The highlight shows chord content, while the inversion control changes which chord tone is in the bass.

Q: Which keys is A7 found in?

The chord acts as a diatonic degree in several keys — they are marked on the circle of fifths in the "Harmonic context" block.

Q: What can I substitute for A7?

A substitution depends on harmonic function and voice leading, not only on shared tones. Computed options appear in the "Substitutions" block and should be checked in context.

A Dominant 7

Octaves

Musical context

ChordA majorTriad

ChordA7A Dominant 7

ArpeggioA majorBroken triad

ScaleA major7 notes

KeyA majorMajor key

ProgressionPop axisSequence

How the chord relates to the scale, mode, key and progression.

Theory

General info

Full name: A Dominant 7
Symbol: A7
Root: A
Quality: Dominant 7

Chord notes

1Aroot

3C#major 3rd

5Eperfect 5th

b7Gminor 7th

Functions & resolutions

Typical function in key: VDominant (V)D major
Stability / tension: High tension — requires resolution
Most common resolutions: DD Major BmB Minor
Unstable degrees: 3C#
4D
resolves up to the resolution tonic
6F#
b7G
resolves down to the tonic 3rd
Main resolution: A7source
DD Major
Dominant 7th A7 naturally resolves up a 4th to D. It is the tritone between the chord's 3rd and 7th that creates this pull.
Other resolutions: A7source
Deceptive resolution
BmB Minor
Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.
A7source
Modal resolution
GG Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
A7source
Jazz reharmonization
D#7D# Dominant 7
Tritone substitution: A7 can be replaced by D#7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.
A7source
Functional resolution
Asus4A Sus4
The dominant can resolve beyond the tonic: moving to IV (subdominant) or to a suspension (sus4) are common alternatives in pop and folk music.

Substitutions

Tritone substitution: Eb7Eb Dominant 7

Features

Character: Dominant, tense
Characteristic interval: Dominant 7th (b7)
Description: The minor 7th adds dissonance to a major triad. On scale degree V, the chord’s 3rd and 7th form a tritone that directs the voices toward tonic.
Application: V chord in major (resolves to I)
12-bar blues
Rock, Mixolydian