What is Metric Modulation?

Metric modulation is a compositional technique in which the tempo of a piece changes through a precise rhythmic relationship between two note values. Instead of a sudden tempo shift, one rhythmic value becomes equivalent to another, creating a smooth transition from one tempo to the next.

In metric modulation, a composer establishes a connection between rhythmic subdivisions so that a note value in the original tempo is reinterpreted as a different note value in the new tempo. For example, a triplet eighth note in one tempo might become a regular eighth note in the following tempo, effectively changing the perceived speed while maintaining a mathematically related rhythmic structure.

Metric modulation became widely used in 20th-century classical and contemporary music, particularly in the works of composers such as Elliott Carter. The technique allows composers to shift tempo fluidly while preserving rhythmic continuity, creating complex and evolving rhythmic structures within a piece.