tonicdominant

Tonic-dominant is a term used in Western tonal harmony to describe the functional relationship between the tonic function and the dominant function within a key. The tonic, anchored by the I chord, establishes the key center and a sense of rest or stability. The dominant, typically the V chord (often extended to V7), creates tension that seeks resolution back to the tonic, producing propulsion and a sense of closure. This tonic–dominant interaction is a central organizing principle of much tonal music.

In practice, pieces move from tonic regions toward the dominant to heighten anticipation and then resolve back to the tonic, often via authentic cadences (V to I) or, less conclusively, half cadences that end on V. The dominant’s pull is reinforced by leading tones and by common voice-leading patterns that emphasize the resolution from V to I. Beyond V, composers prolong the dominant function through cadential extensions, such as the cadential 6/4, and via secondary dominants (for example V/V or V/ii) that temporarily tonicize other scale degrees before returning to the tonic.

Ton ic-dominant analysis focuses on how phrases and sections emphasize I and V, sometimes outlining a tonal axis or discourse of departure and return. While the concept is central to tonal music, non-tonal or modal traditions may treat tonic and dominant in less prescriptive ways, using the same terms to describe contrast between resting and forward-driving functions rather than strict functional harmony.