Dominant

The function

Of the three main functions of harmony, tonic, subdominant and dominant, the dominant is the one with the greatest tension. Built on the fifth degree, it contains the leading tone, which pulls a semitone upwards to the tonic. The dominant is therefore the opponent of the tonic, the pole of rest. Functional theory, after Hugo Riemann, calls it D for short.

Dominant seventh chord

If you add the minor seventh to the triad, G7 arises. This chord contains the tritone between B and F, and both notes press in opposite directions towards resolution. The cadence G7–C is so inevitable that it forms the ending of very many pieces of Western music between 1650 and 1900. The dominant seventh chord is also the foundation of the blues: practically every blues piece begins or ends with a seventh chord.

Dominant in minor

In natural minor the fifth degree is a minor chord that lacks the leading tone, in A minor Em. That is why the seventh degree is raised (G♯). The dominant then becomes E major, and the close to A minor has pulling power. More on this under A minor.

Dominant on the circle of fifths

On the circle of fifths the dominant lies a fifth above the tonic. In C major the strongest chord movement, a fifth downwards, leads from G to C. A secondary dominant is a dominant chord that resolves to a chord other than the tonic: in C major the dominant of the dominant is D7, which resolves to G.

Common mistakes

• Mixing up dominant and tonic: The tonic is rest, the dominant tension.
• Seeing the dominant only as a chord: It is also the fifth degree of the scale.
• Using v instead of V in minor: For a working cadence the dominant in minor needs the raised leading tone.