A dominant 7 chord is the V7 chord in any key—the chord built on the fifth scale degree, constructed as a major triad with a minor 7th interval added on top. In the key of C major, for example, the V7 is G7 (G–B–D–F).
Why does this matter? The dominant 7 creates sonic tension. The tritone interval—also called a diminished 5th or augmented 4th, spanning 6 semitones—sits between the 3rd and 7th notes of the chord. Historically, musicians called this interval “diabolus in musica” (the devil in music) because it sounded so unstable and dissonant. That tension is exactly what makes V7 so useful: it pulls hard toward resolution to the I chord.
Play a G7 and listen to how much it “wants” to resolve to C major. That pull is the harmonic magic of the dominant 7.
The tritone: why dominant 7 sounds urgent
The tritone in G7 is the interval between B (the 3rd of the chord) and F (the 7th). B to F is exactly 6 semitones—dead center between a perfect 4th and a perfect 5th, which is why it sounds unresolved and restless.
When that G7 resolves to C major, the B steps up to C and the F steps down to E. Each note moves by just a half step, and suddenly the tension dissolves into stability. This voice leading—the smooth stepwise motion of individual notes—is what makes dominant function work so powerfully.
You’ll hear this pattern in virtually every blues song, jazz standard, and rock ballad. Once you recognize the sound, you’ll start noticing V7 resolve to I everywhere. If you want to explore how this fits into chord progressions more broadly, learn how musicians build intentional progressions with tension and release.
Dominant 7 voicings on guitar
There are several ways to voice a dominant 7 on guitar. Here are the most practical:
The open E7 voicing (if your key is A major) uses the open E shape: play the low E open, then fret 1–2–1 on the A–D–G strings. This is bright and ringing, perfect for blues and rock.
The barred F7 voicing works in any key as a moveable shape. Barre your index finger across an entire fret, then add your middle finger two frets up on the D string, and ring finger three frets up on the B string. Slide this shape up or down to play any dominant 7. In the key of Bb, play it at the 1st fret to get Bb7; for G7, play it at the 10th fret. This is essential for jazz and funk.
The compact dominant 7 without the root simplifies things. Play the b7, 3, and 5 without doubling the root note. This works great in a band context where the bass player handles the root. It’s leaner and lets other instruments shine.
Dominant 7 with extensions adds color and sophistication. A G7#5 (G–B–D#–F) sharpens the 5th, creating a subtle alteration. A G7b9 (G–B–D–F–Ab) flattens the 9th and adds blues flavor. These are common in jazz and funk; experiment once you’re solid on the basic voicing.
To see how these fit alongside other chord types and positions, explore a full guitar chord chart with finger positions and diagrams.
Dominant 7 in blues progressions
The blues progression is the most famous home for dominant 7. In a 12-bar blues in C, you play:
- 4 bars of C7 (I7 – yes, the tonic gets the dominant treatment in blues)
- 2 bars of F7 (IV7)
- 2 bars of C7 (I7 again)
- 1 bar of G7 (V7)
- 1 bar of F7 (IV7)
- 2 bars of C7 (I7)
Every chord is a dominant 7. That’s the blues sound: perpetual tension and swagger, never fully resolving. If you’re learning blues guitar, this pattern is non-negotiable. The V7–I turnaround (G7 back to C7) at the end of each 12-bar cycle is what makes blues feel complete and ready to start over.
For more on blues progressions and how they use these chords, dig into the 12-bar blues progression guide.
Secondary dominants and advanced usage
Once you’re comfortable with the basic V7 resolving to I, you can explore secondary dominants. A secondary dominant is a V7 that resolves to a chord other than the tonic. In the key of C, you might play D7 resolving to G (the ii chord), or B7 resolving to E (the iii chord). This technique adds harmonic sophistication and is everywhere in jazz.
For example, in a jazz standard, you might see:
- Cmaj7 (I)
- B7 (secondary dominant to the next chord)
- Em7 (iii, the target)
- A7 (secondary dominant)
- Dm7 (ii, the target)
Each secondary dominant pulls the ear toward a temporary harmonic center before resolving. It’s advanced stuff, but once you recognize it, you’ll hear it in every bebop solo and modern jazz arrangement.
Explore jazz guitar chords and their harmonic functions to dig deeper into secondary dominants and other jazz vocabulary.
Frequently Asked Questions
Is dominant 7 only used in jazz and blues?
No. V7 appears in pop, rock, soul, funk, R&B, and nearly every other genre. It’s a fundamental harmonic tool. Blues and jazz just emphasize it more heavily and use it in more complex ways. Any time you want a strong pull toward resolution, V7 is your chord.
What’s the difference between V7 and just V (major)?
V (major, e.g., G major) is stable and resolved-sounding. V7 (G7) contains the tritone, which is tense and unresolved. The tritone is what creates the “pull” toward I. Use V7 when you want that tension and resolution; use V major when you want something more stable and less driven.
Can I play dominant 7 with open strings?
Yes. E7 is the easiest open dominant 7—just play the open E chord and add your middle finger on the 2nd fret of the A string. This gives you E–G#–B–E–D, which includes the b7 (D). From there, you can move it around the fretboard using barre shapes.
How do I know when to use a dominant 7 in my song?
Use it when you want to create a push toward the next chord. In a progression, V7 is almost always followed by I (the tonic). If you’re in the key of G, after you play an E7 or a secondary dominant like F#7, resolve it back to your target chord within one or two beats. The tension-release cycle is short and clear.
Daniel Murphy is a guitar theory and chord analysis writer at GuitarChordIdentifier. He focuses on chord recognition, guitar harmony, music theory, and interactive learning tools for guitarists, musicians, songwriters, and beginners.