Towards a systemic theory of rhythmic modes in Wesst Afrcian musical studies
Current studies on African rhythm are characterized by the absence of a formalized theoretical framework for describing rhythm on a conceptually analytical level. This paper offers a formal theoretical framework within which the problem of rhythm can be more systematically studied. During an examination of scores of Yoruba drum music, it was observed that the continuous repetition of ‘rhythmic ostinato' was the structural framework upon which an entire composition is often organized. Some rhythmic ostinato were then extracted from some composition and compared with those of the music of neighboring groups such as the Edo, Fon and Ewe. It was discovered that the so-called ‘standard twelve-beat pattern' exists in various forms which literally speaking are ‘modes'. More important is that other ‘modes' can be generated from a given mode by starting at different points within the “rhythmic cycle” in a way analogous to the derivation of modes in scale construction. A mode can also be generated through a retrograde inversion of the other. A formal table was then constructed showing the number of modes derivable from the ‘standard twelve-beat pattern'. Using this approach, rhythmic patterns that are generically related can be grouped together as modes and given a nomenclature.
Nigerian Music Review Vol. 6 2005: pp. 9-26