Music theory explained

Seventh chords are used to create tension and resolution, as the dissonance in a chord tends to resolve into a more stable sound.

For example, the dominant seventh chord (V7) is commonly found in many styles of music because it strongly gravitates toward the tonic chord (I), creating a sense of tension and resolution:

Leading-tone seventh chord (VII7)

The supertonic seventh chord (II7)

Seventh chords can be used in a various musical contexts, including jazz, blues, classical, and popular music. They add harmonic color and expression, enabling composers and musicians to create diverse and engaging musical compositions.