Microtiming Patterns and Interactions with Musical Properties in Samba Music

Abstract

In this study, we focus on the interaction between microtiming patterns and several musical properties: intensity, meter and spectral characteristics. The data-set of 106 musical audio excerpts is processed by means of an auditory model and then divided into several spectral regions and metric levels. The resulting segments are described in terms of their musical properties, over which patterns of peak positions and their intensities are sought. A clustering algorithm is used to systematize the process of pattern detection. The results confirm previously reported anticipations of the third and fourth semiquavers in a beat. We also argue that these patterns of microtiming deviations interact with different profiles of intensities that change according to the metrical structure and spectral characteristics. In particular, we suggest two new findings: (i) a small delay of microtiming positions at the lower end of the spectrum on the first semiquaver of each beat and (ii) systematic forms ofaccelerando and ritardando at a microtiming level covering two-beat and four-beat phrases. The results demonstrate the importance of multidimensional interactions with timing aspects of music. However, more research isneeded in order to find proper representations for rhythm and microtiming aspects in such contexts.

Acknowledgements

This study was supported by a Short Term Scientific Mission financed by the COST IC0601 Action on Sonic Interaction Design, by a grant from Ghent University (Belgium) and partly by CAPES (Brazil). The authors wish to thank Inaê Benchaya Duarte for the annotation files.

Notes

¹For example, acculturated performers would be recognized by their ability to perform systematic deviations (and interactions). This ability may be linked with subjective qualities attributed toskilled musicians or performances such as the ‘balanço’ (balance), ginga (close to groove and related to body movements) or ‘suingue’ (swing). See Gerischer (2006) for other examples.