tempovariation

Tempovariation, also written as tempo variation, refers to fluctuations in tempo over time within a musical piece or performance. It describes deviations from a reference or notated tempo, whether intentional for expression or arising from performance constraints. The term is used in musicology, performance practice, and music analysis to describe how tempo changes occur within a passage and how they affect interpretation.

In practice, tempovariation encompasses both controlled tempo rubato and more explicit tempo changes such as accelerando and ritardando. Rubato involves flexible speeding up or slowing down for expressive effect, while accelerando and ritardando denote deliberate tempo directions in the score or performance. Not all tempo fluctuations are stylistically appropriate; performers balance expressiveness with continuity, phrase shape, and formal structure.

Measurement and analysis of tempovariation typically estimate local tempo across successive segments, then compute statistics such as the mean tempo, standard deviation, or coefficient of variation. Graphical tempo curves and distributions of inter-beat intervals are common tools. Different genres establish different expectations for tempovariation: classical music often emphasizes controlled and cohesive tempo behavior, whereas Romantic and contemporary styles may invite broader expressive variation.

Beyond music, the concept appears in biomechanics and motor control when describing variability in cadence or tempo of repetitive actions, though it is used less formally in those fields. In all domains, tempovariation helps describe how timing and tempo contribute to perception, expression, and performance quality.