The dominant seventh chord adds a minor seventh above the root to a major triad. It is the defining sound of dominant function: tension that wants to resolve, especially to the tonic. Charts show C7, G7, and so on. Blues, jazz, gospel, rock, and classical harmony all lean on this chord as the engine of cadences.
How it’s built
Major triad plus minor seventh interval. In C7: C–E–G–B♭. The interval between the third (E) and the seventh (B♭) is a tritone—the acoustic heart of dominant tension in common-practice harmony.
Usage
In blues, the dominant seventh is often treated as a static color on I as well as V. In jazz, V7 leads to I in countless progressions and supports improvisation with mixolydian and bebop lines. In pop and rock, V7 appears in turnarounds and cadences; in classical, it is the workhorse of authentic cadences.
Examples
- Blues shuffles and jazz standards — dominant sevenths everywhere
- Rock and soul — V7 before I in endings and turnarounds
- Baroque–Romantic classical — dominant seventh in authentic cadences
Play
Practice V7 → I with smooth voice-leading; shell voicings (root–third–seventh) teach the sound before you add extensions like 9 or ♭9.
