Polyrhythmie

Polyrhythmie, often called polyrhythm, refers to the simultaneous use of multiple rhythmic layers that have different subdivisions or meters within the same musical period. In a typical example, one layer may play two evenly spaced notes per beat while another plays three, producing a 2 against 3 relation. The rhythms align at regular points and diverge in between, creating a complex texture.

Historically and cross-culturally, polyrhythms are prominent in West African drumming traditions (for example Ewe and Akan ensembles), Afro-Cuban music, and various forms of South Asian and Balkan music. They are also studied in contemporary classical and jazz, where musicians may layer different meters or employ phase-based techniques.

Notationally, polyrhythms can be notated with multiple voices or using cross-staff notation, and performers often practice by subdividing the beat with a metronome or by clapping the simultaneous patterns separately before combining them. Common simple cases include 2:3, 3:4, or 4:5 relationships, while more complex polyrhythms may involve longer cycles.

Polyrhythmie is related to, but distinct from, cross-rhythm and hemiola: cross-rhythm emphasizes secondary metric cycles against the main meter, while hemiola involves the perception of rhythm intensification or reduction within a single meter, such as 3:2 over a barline. The term highlights the richness of rhythm in global musical practice.