What is a Dominant Seventh Chord?

A dominant seventh chord is a four-note chord made up of a root, a major third, a perfect fifth, and a minor seventh. This combination of intervals creates a strong and slightly tense sound that naturally wants to resolve to another chord. For example, a C dominant seventh chord (C7) contains the notes C, E, G, and B♭.

The defining feature of a dominant seventh chord is the interval between the root and the seventh, which is a minor seventh, combined with the major third. This pairing creates a noticeable tension in the harmony. Because of this tension, dominant seventh chords are often used to lead into another chord, especially the tonic chord in a key.

Dominant seventh chords are widely used in many musical styles including blues, jazz, rock, funk, and pop music. They are a key part of common chord progressions and help create movement and resolution within a song. Their distinctive sound makes them one of the most important chords in modern music harmony.