Time Structure in the Music of Central Africa: Periodicity, Meter, Rhythm and Polyrhythmics

Abstract

Rhythm in Central African music is based on a strictly periodic structure. The period is internally organized on two levels: by the pulse and by the minimal operational values. Rhythm consists in the imposition of cyclic figures—with or without variations—on an underlying period. Rhythmic figures can be defined by a set of five features: mark, durations, morphology, metricity and structure. The dominant rhythmic feature in Central Africa is a contrametric relationship to the pulse, which creates an antagonism between the rhythmical events and their temporal framework. Polyrhythmic music results from the interaction of two or more superposed rhythmic figures, which may vary in dimensions but have periods standing in simple ratios, and its dominant feature is the interweaving of accents, tone colors and/or attacks of the simultaneously performed figures. This gives rise to a conflict between rhythm and rhythm, which is coupled with the antagonism between rhythm and meter characterizing each individual figure. Many of the phenomena described in this paper are current over a much wider area of sub-Saharan Africa.