semicord

G7 G dominant seventh chord

Notes
G B D F
Formula
1 3 5 b7
Semitones
0 4 7 10 above the root
Other symbols
Gdom7

G to B is a major third (4 semitones), B to D is a minor third (3 semitones), D to F is a minor third (3 semitones). A dominant seventh is a major triad plus a minor seventh (F, 10 semitones above G). It is the V chord that leads back home, and the basic chord of the blues.

G7 on the piano

C4D4E4F4G4A4B4C5D5E5F5G5A5B5C#4Eb4F#4Ab4Bb4C#5Eb5F#5Ab5Bb5C4GBC5DF

Root position from G4: G4, B4, D5, F5. Middle C is C4.

G7 on the guitar

Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has G as its lowest note.

GGBBDGBFF
Open position
3 2 0 0 0 1 (low E to high e)
Sounds G2 B2 D3 G3 B3 F4
GGDDFFBBDDGG
E-shape barre, root on the E string at fret 3
3 5 3 4 3 3 (low E to high e)
Sounds G2 D3 F3 B3 D4 G4
10fr×GGDDFFBBDD
A-shape barre, root on the A string at fret 10
x 10 12 10 12 10 (low E to high e)
Sounds G3 D4 F4 B4 D5

The barre shapes are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play dominant seventh chords on other roots.

Inversions of G7

An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.

PositionNotes, bass firstNamedListen
Root positionG B D FG7
1st inversionB D F GG7/B
2nd inversionD F G BG7/D
3rd inversionF G B DG7/F

Where G7 fits

G7 is V7 in C major, V7 in C minor. Its B and F are a tritone apart (6 semitones). In C major the B usually rises a half step to C and the F falls a half step, which is why G7 pulls so strongly towards C.