Hemiola
A regrouping of three-beat and two-beat units within the same metre
Related
Hemiola regroups durations from three to two, or two to three, within one metrical framework. The classic form turns two units of three beats into three units of two, as in 3/2, or shifts the accent between 6/8 and 3/4.
It is common before cadences in Renaissance and Baroque music: the lower parts continue while the upper parts press the triple feel into duple and drive the close. Romantic composers used it for suspension, and it is easy to hear in Brahms.
Hemiola is not polyrhythm. It is usually brief, regroups the existing metre and need not change the time signature, whereas polyrhythm sets different equal divisions running together. To hear it, keep the original triple pulse and count the competing duple accents.
Sources
- 定义、记谱与终止用法参 The New Grove Dictionary of Music and Musicians, "Hemiola"；本文为原创表述
Used for fact-checking only; all prose is original.