Polak’s (2010) chronometric analyses of Malian jembe music suggested that the characteristic “feel” of individual pieces rests upon nonisochronous subdivisions of the beat. Each feel is marked by a specific pattern of two or three different subdivisional pulses—these being either short, medium, or long. London (2010) called the possibility of more than two different pulse classes into question on psychological and theoretical grounds. To shed light on this issue, 23 professional Malian percussionists and dancers were presented with timing-manipulated phrases from a piece of Malian drumming music called “Manjanin.” In a pairwise comparison experiment, participants were asked: (1) if the items of each pair were same or different, and (2) if different, which of the two was the better example of the characteristic rhythm of Manjanin. While most contrastive pairs were well distinguished and produced clear preference ratings, participants were unable to distinguish short-medium-long patterns from short-long-long patterns, and both were preferred to all other manipulations. This supports London’s claim that, perceptually, there are only two pulse classes. We discuss further implications of these findings for music theory, involving beat subdivision, tempo effects, microtiming, and expressive variation, as well as methodological issues.
Comparison experiment on the sputtering of EUROFER, RUSFER and CLAM steels by deuterium ions
