Chord Shapes

Dominant 7th

Intervals: 1-3-5-b7. The dominant 7th is the workhorse V chord in tonal and jazz harmony. Its defining feature is the tritone between the 3rd and b7, which creates strong functional pull to a chord a perfect 4th above (or 5th below) – typically the tonic or a temporary key centre. In classical-style cadences B (3rd of G7) resolves up to C and F (b7) resolves down to E, but in jazz this basic pattern is embellished with added 9ths and 13ths as standard. Dominant 7ths appear as primary V chords, secondary dominants in circle-of-fifths chains (e.g. A7–D7–G7–C7 in “Fly Me to the Moon”), and as non-resolving blues dominants on I, IV and V. In blues and rhythm changes, whole progressions can be built almost entirely from dominant 7ths, creating a bright, edgy, forward-driving sound that constantly hints at resolution without always delivering it.