What does "additive meter" refer to?

Additive meter refers to a rhythmic structure where the beats are grouped in irregular patterns or combinations, often adding together to form larger units. This means that the individual beats or pulses can vary in number per measure, creating a feel that is not strictly uniform. For instance, a time signature like 7/8 can be broken down into smaller patterns, such as a combination of groups of 2 and 3, resulting in a unique rhythmic texture.

This concept contrasts with more conventional meters, which typically rely on consistent subdivisions into equal groups, such as simple or compound meters. In those cases, each measure usually maintains a regular, predictable structure, which does not align with the characteristics of additive meters. The irregular grouping found in additive meter fosters a sense of fluidity and can evoke different emotional responses in music. Thus, the defining feature of additive meter is the freedom and diversity in how rhythmic patterns unfold and aggregate.