A7 Chord on Guitar: The Bluesiest Two-Finger Chord

A7 is the cheapest harmony upgrade in guitar. Two fingers, one fret, and your A major just got a tension that wants to fall toward D. It's the chord that makes the blues sound like the blues. It's also, mechanically, easier than A major.

A7 is built from A, C sharp, E, and G. The G is the dominant 7th, the note that gives the chord its restless, leaning-forward quality.

The Standard A7 Fingering

• 1st string (high E): open
• 2nd string (B): 2nd fret, ring finger (or middle, dealer's choice)
• 3rd string (G): open
• 4th string (D): 2nd fret, index finger (or middle)
• 5th string (A): open
• 6th string (low E): do not play

Strum strings 1 through 5. Two fingers, both at the 2nd fret. The notes from low to high are A, E, G, C sharp, E. The G note (open 3rd string) is the dominant 7th.

How A7 Differs From A Major

The only difference between A and A7 is one note. In open-position A major, you press the 2nd fret of the G string with your middle finger to fret a C sharp. In A7, you lift that finger off and let the open G ring instead. That single open string adds the 7th and turns the chord from a stable major into a tension chord.

This is why A7 is mechanically easier than A. You're using one fewer finger.

Why A7 Sounds Bluesy

Dominant 7th chords (chords with both a major 3rd and a flatted 7th) sound bluesy because they're harmonically unresolved. The 7th wants to fall by a half step, which creates the gravitational pull toward the next chord. In A7, the G note wants to fall to F sharp, which lives inside the next-likeliest chord (D major).

The blues uses dominant 7ths on every chord (I7-IV7-V7), which is technically wrong by classical theory rules. The result is a sound that's saturated with tension and never fully resolves. That tension is the blues.

Songs That Use A7

• Almost any 12-bar blues in A. A7-D7-E7 is the canonical A blues progression.
• "I Saw Her Standing There" by The Beatles uses A7 in the verse.
• "Twist and Shout" rotates through A7, D, E.
• Honky-tonk and ragtime. Both styles lean on dominant 7ths constantly.

A7 Variations

• A7sus4. From A7, add the pinky on the 3rd fret of the 2nd string. The C sharp becomes D, the chord becomes suspended. Used in the verse of "Wonderwall".
• A9. Add the 9th (B) on top of A7. Common in funk and soul.
• A13. The full jazz extension, with the 13th (F sharp) added. Tricky to fret.

The fretboard explorer shows every A7 voicing on the neck, including the 5th-fret barre version that some players prefer for its fuller sound.

The A7 to D Resolution

The single most useful chord change involving A7 is A7 to D. The G note in A7 falls a half step to F sharp (which is the 3rd of D major). The C sharp in A7 falls a half step to... wait, the C sharp stays as the 7th of D... no, D major doesn't have a 7th. The C sharp resolves to D. The chord change has built-in voice leading.

This is why blues progressions feel so satisfying. The harmonic gravity is doing the work for you.

FAQ: A7 Chord Questions

Is A7 a major or minor chord?

Major. The "7" only refers to the added 7th note (G). The base chord is still A major. Am7 (A minor 7) would have a flat third (C natural instead of C sharp).

Why is A7 called a "dominant" 7th?

Because in classical music, the V chord (the dominant) of any key gets the dominant 7th treatment. In the key of D major, A is the V chord, so A7 is the dominant 7th. The chord wants to resolve to D.

Can I substitute A7 for A in any song?

Sometimes. A7 has more tension than A and wants to resolve. If a song stays on A for several bars, substituting A7 will create a forward-leaning quality that may or may not fit. In blues, always substitute the 7th. In gentle ballads, often don't.

Is A7 easier than A major?

Mechanically yes. You use one fewer finger and leave the 3rd string open instead of fretting it.

What's the difference between A7 and Amaj7?

The 7th is different. A7 (also called A dominant 7) has G natural as the 7th. Amaj7 (A major 7) has G sharp as the 7th. They sound very different. A7 is bluesy and tense; Amaj7 is dreamy and unresolved in a softer way.