Author: Guerra, Stephen P.
Title: Expanded Meter and Hemiola in Baden Powell\'s Samba-Jazz
Institution: Yale University
Begun: January 2015
Completed: April 2018
Afro-Brazilian guitarist-composer Baden Powell de Aquino (1937-2000), one of Brazil’s earliest and most successful international guitarists, is renowned for his inexplicable rhythmic style. This is especially true in the context of instrumental samba, or samba-jazz, which emerged in the late-night music clubs of 1950s-60s Rio de Janeiro. Samba-jazz engages a set of normative expectations: (1) a theme-and-variations performance involving a (2) cyclic scheme of regular and even chord changes comprising (3) a form of often 16 or 32 bars traditionally conceived of as being in duple meter (e.g. 2/4), where (4) improvised variations track the chord changes of the form. Against this recursively even, duple-meter background, Baden’s chord-melodic improvisations frequently foreground dotted or asymmetrical rhythms that, in their interaction with the duple frame, suggest uneven periodicities. This study argues that such uneven regularities can, under certain conditions, be defined as metric and as such can be treated as participating in generalized hemiolas of the background form’s meter. This two-fold expansion of meter and hemiola leads to the discovery of a much larger and more variegated abstract space constituted by the even and uneven metric possibilities for a given span of musical time.
This dissertation consists in two complementary projects. The theoretical project expands current theories of meter, hemiola, and metric space, as most recently defined by Richard Cohn (2018), to incorporate Justin London’s (2012) theory of non-isochronous meters. The analytical project explores the richness of Baden’s rhythmic art—it’s metric implications and relationship to tropes of samba-jazz.
Keywords: meter, hemiola, metric space, non-isochronous, samba, Baden Powell, Brazil, prime generation, quantization
Note to Readers
Chapter 1: The Meter of Baden’s Rhythm
Chapter 2: Expanded Meter, Hemiola, and Metric Space
Chapter 3: Rhythmic Tropes in Samba-Jazz
Chapter 4: Harmonic Quantization
Chapter 5: Hemiola and Form