Dissertation Index

Author: Hosken, Fred

Title: The Pocket: A Theory of Beats as Domains

Institution: Northwestern University

Begun: September 2016

Completed: August 2021


This dissertation proposes a theory that views beats as probabilistic domains that I term “pockets,” taking a vernacular term commonly used by jazz, funk, and popular music performers to describe the state of being in a good groove and making it concrete through empirical methods. Pockets have three key properties: they are domains of time, whose membership is probabilistic, and the specific shape of the probabilistic distribution is associated the qualitative experience of a performance—its “feel.” The theory of pockets that I advance can be utilized to provide new perspectives on rhythmic structures in music, as well as new approaches to understanding patterned microtiming in performance, the phenomenon of musical “groove,” and musical “feel” more generally. Pockets are a complement to Danielsen’s theory of perceptual “beat bins” (2010), theorizing extended beats in the sound signal of performances. By importing the term “pocket,” the technicalities of the shaping of music time can be made meaningful by drawing on real-world qualitative descriptors of “feel”—a pocket may be “loose” or “tight,” a performer can “lay back,” be “on top of the beat,” or “push.”

I first survey, in Chapter 1, the literature, drawing together the established theories of beats
in music and cognitive research and arguing that there is a need for a theory of beats that prioritizes the sound signal produced by performance events. Chapter 2 introduces the theory of pockets, justifies why the label “pocket” is so important (rather than simply “domain”), and establishes the existence of pockets with a music information retrieval analysis of three corpora of drum performances. Chapter 3 considers what these pockets mean for the listener experience, introducing descriptive terms that might be used to make sense of timing variations between performances. Chapter 4 presents an empirical study that explores whether listeners are able to perceive subtle timing differences. And finally, Chapter 5 considers how differently shaped pockets interact with form in popular music, analyzing Stevie Wonder’s “Superstition” to argue that musicians manipulate the shape, size, and location of the pocket across a song to enhance the experiential qualia of different sections.

Keywords: Rhythm, Perception, Performance, Music information retrieval


1. Beats in Theory & Cognition: Sounded and Perceived
2. The Theory of Pockets
3. Individual Performer's Pockets & Feels
4. The Perception and Discrimination of Different Musical "Feels"
5. Dynamically Changing Pockets and Form in "Superstition"


Fred Hosken

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