G Dominant 7th Chord: Notes, Voicings, and How to Play It

Eleven of the twelve dominant sevenths need at least one black key. G7 does not. Its notes are G, B, D and F, and no other chord of this type can be built without leaving the naturals. That accident is why it tends to be the first seventh chord in a method book: a teacher working in C major can introduce the whole idea of a four note chord before introducing a single accidental.

Inside those four plain notes sits the only tritone the white keys contain. B against F, three whole tones apart, the interval choir singers were once warned off as mi contra fa. Everything this chord does, it does because of those two.

Try It: G7 in the Chord Finder

The Notes of G7

The seventh is F natural, not the F♯ that G major’s key signature would suggest, and that single natural is what points the chord away from G and towards C. The symbol is bare: G7.

How G7 Is Built

Take G major, G B D, and add the note a whole step below the octave. F sits a minor 3rd above D, so the chord is still a stack of thirds, one storey taller.

The new interval is the one that matters. B up to F spans six semitones, written as a diminished 5th because the letters run B, C, D, E, F. Six semitones is exactly half an octave, which is why neither note sounds like a resting place.

Strip the chord back and the tritone survives. G, B and F alone is still unambiguously G7. Keep only B, D and F and you have a B diminished triad, which is why a Bdim can stand in for this chord.

G7 on the Piano

Four white keys, taken 1 on G, 2 on B, 3 on D and 5 on F in the right hand, 5, 3, 2, 1 in the left. The span is a minor 7th, a reach for a small hand but flat and even, with nothing set back into the black key region.

Now look at where the tritone sits, because this is the whole of tonal music in one picture. Only two white keys have a white key immediately above them, E and B; only two have a white key immediately below, C and F. The chord’s B has C right next to it, a semitone up. Its F has E right next to it, a semitone down. Both of the notes under pressure can move without touching a black key at all.

Drill it with two fingers. Put 2 on B and 4 on F, then let 2 rise to C and 4 fall to E. The voices travel towards each other, a semitone each, and the six semitone gap closes to a major 3rd. That contraction is the engine of every perfect cadence you have heard, and here it happens between the two plainest notes on the instrument.

Add the rest and a curiosity appears. With G in the left hand and B, D, F in the right, move the left hand to C, let B climb to C and F drop to E, and the only free note is D. Send it either way and the C major you land on has a doubled note and no fifth. Leave the D out of the G7 instead and the tonic can be complete: a full dominant buys an incomplete tonic, and nobody misses either fifth.

G7 on the Guitar

The open form is 3 2 0 0 0 1, sounding G, B, D, G, B and F. Ring finger on the 6th string at the 3rd fret, middle on the 5th at the 2nd, index on the 1st string at the 1st fret. Anyone who already fingers G major with the little finger on top has only to lift it and drop the free index onto the 1st fret.

That index is working at the wide end of the neck. Frets shorten as they climb, so holding the bottom string at the 3rd fret and the top string at the 1st opens the hand across the widest spacing on the instrument. Beginners often deaden the B string with the underside of the reaching finger.

The best thing about this shape is that the tritone lands on the top two strings, side by side. The open B string is the chord’s third; the F at the 1st fret of the top string is its seventh. Play those two alone, then resolve them: move the index across one string to the 1st fret of the B string, which is C, and let the top string ring open as E. One finger crosses one string and you are holding the top half of an open C chord.

Away from the nut, the E7 shape barred at the 3rd fret gives 3 5 3 4 3 3, easier than the G major barre at the same position: the seventh lets the 4th string fall back onto the barre and frees a finger that the major shape needs. The A7 shape at the 10th fret, x 10 12 10 12 10, is thinner and sits where the frets are cramped.

For playing with other people, use the shell. 3 x 3 4 x x gives G on the 6th string, F on the 4th and B on the 3rd: root, seventh, third, with the tritone again on neighbouring strings. It cuts through an arrangement that the six string form would thicken.

Inversions

Each bass note commits the chord to a different approach. G7/B puts the leading tone underneath, so the bass itself takes the semitone step to C. G7/F is the everyday one: a seventh in the bass has to fall to E, so what follows is C/E rather than root position C, and a bass walking G, F, E through this chord is one of the commonest gestures in the repertoire.

Voicings

The fifth is expendable, the tritone is not. G, B, F says everything the full chord says with three notes. Drop the root instead and B, D, F is a diminished triad that a bass player’s G turns back into a dominant.

Which way round the tritone sits changes the gesture without changing the destination. B below F is a diminished 5th and the two voices close inwards onto C and E. F below B is an augmented 4th, and the same two notes open outwards onto E and C. Opposite motion, identical arrival, and arrangers choose according to whether the texture should tighten or spread.

Which Keys Contain G7

• V of C major
• VII of A natural minor
• V of C harmonic minor
• V of C melodic minor
• I of G mixolydian
• IV of D dorian

Three of those six are C: major, harmonic minor and melodic minor. The dominant of a key is the same chord whether the key is major or minor, which is why a piece can swap between C major and C minor without renegotiating its cadences.

G mixolydian is the odd one out. A mode built on G with an F natural in it makes the dominant seventh the tonic, so nothing needs to resolve and the same four notes become a place to sit.

Where G7 Shows Up

The last row is the tritone taken seriously. D♭7 contains F and C♭, and C♭ is B under another name, so the substitute holds the same two notes that made G7 restless. Swap one for the other and the tension survives while the bass slides chromatically into C. That trick exists only because the tritone belongs to two dominants at once.

The blues row does the opposite. In a twelve bar blues in G every chord is a dominant seventh, so the style keeps the tension and declines to resolve it.

The chord also visits its own key. In a song in G major the seventh above the root ought to be F♯, so an F natural is an accidental on the page and a signal in the ear: the tonic has become the dominant of C. Folk and gospel writing in G leans on that move constantly.

Related Chords

• G Major Chord, the triad this is built on
• G Sus4 Chord, which delays the third that makes the tritone
• G Major 6th Chord, the other four note chord on G with no black keys
• G Augmented Chord, whose raised fifth turns this into G7♯5
• Secondary Dominants and Borrowed Chords
• Extended Chords and Jazz Harmony for G9 and G13
• The G Mixolydian Scale
• Guitar Chord Shapes: The CAGED System

Learn More

• Seventh Chords: A Complete Guide
• Diatonic Chords: A Beginner’s Guide
• Chord Inversions and Voice Leading
• The Circle of Fifths Explained
• Chord Progressions Every Musician Should Know