What notes are in an A7 chord?

A7 contains four notes: A (root), C♯ (major third), E (perfect fifth), and G (minor seventh).

How do you play A7 on guitar?

The open A7 voicing is x02020: mute the low E, then open A, E (2nd fret 4th string), open G, C♯ (2nd fret 2nd string), open high E.

How is A7 different from Amaj7?

Only the seventh changes. A7 has G natural; Amaj7 has G♯. A7 sounds bluesy and pulls toward D; Amaj7 sits stably as a tonic.

Every D-major folk and country tune uses A7 at cadences. Every A blues uses A7 as the I chord. Hank Williams' classic country writing in A and D leans heavily on A7. Robert Johnson's blues recordings are full of A7 voicings.

A dominant 7 chord — notes, intervals, and practice

A dominant 7 (A7) — A, C♯, E, G — is A major with a minor 7th. On guitar, the open A7 voicing (x02020) is one of the easiest chords to finger because open strings carry three of the four notes. The chord is the V7 of D major and the I7 of A blues — a guitar-friendly blues key alongside E.

Intervals

The A dominant 7 chord stacks two thirds on the root. Each interval and its size in semitones:

A→C#major 3rd4 semitones
C#→Eminor 3rd3 semitones
E→Gminor 3rd3 semitones

On the keyboard

Each note of the A dominant 7 chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the A dominant 7 chord on a six-string guitar fretboard.

1A
3C#
5E
♭7G

Common mistakes

A7 has G natural as its 7th — a half-step lower than Amaj7 (which has G♯). Replacing G with G♯ produces Amaj7 (a stable tonic chord). The blues-defining G natural is what makes A7 sound bluesy. On guitar, the open A7 (x02020) uses open strings for A, E, and G — making it ring out fully.

In context

A7 is the V7 of D major (A7 → D is the cadence in every D-major folk and country tune) and the I7 of A blues. The 12-bar blues in A is built on A7, D7, and E7. In ii–V–I in D major, the progression runs Em7 → A7 → Dmaj7.

Drill it

The A dominant 7 chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

Open the Chord Trainer →Or try today's Etudle puzzle

Frequently asked

What notes are in an A7 chord?: A7 contains four notes: A (root), C♯ (major third), E (perfect fifth), and G (minor seventh).
How do you play A7 on guitar?: The open A7 voicing is x02020: mute the low E, then open A, E (2nd fret 4th string), open G, C♯ (2nd fret 2nd string), open high E.
How is A7 different from Amaj7?: Only the seventh changes. A7 has G natural; Amaj7 has G♯. A7 sounds bluesy and pulls toward D; Amaj7 sits stably as a tonic.
What pieces use A7?: Every D-major folk and country tune uses A7 at cadences. Every A blues uses A7 as the I chord. Hank Williams' classic country writing in A and D leans heavily on A7. Robert Johnson's blues recordings are full of A7 voicings.