Dominant Seventh Chord

The Dominant Seventh Chord (often abbreviated as V7 or simply Dominant 7) is a four-note chord composed of a root, major third, perfect fifth, and minor seventh. Its sound is inherently unstable and 'tense', creating a very strong urge to resolve to the tonic chord (the I degree). This tension primarily derives from the presence of the 'tritone' (an interval of three whole tones, for example between the major third and the minor seventh) within it, making it the main engine of harmonic progressions in the tonal system. For example, a G7 is composed of G, B, D, F. It is the most crucial chord for generating harmonic movement and tension, anticipating a resolution.

Common Progressions

• V7 - I (the fundamental resolving progression in almost all tonal music)
• ii - V7 - I (the jazz progression par excellence, it creates a strong and direct movement towards the I degree)
• I - IV - V7 (an extension of the I-IV-V progression, where the V now includes the dominant seventh for greater tension before resolution)