My dissertation—Groove: The Phenomenology of Musical Nuance (2007)—has to do largely with rhythm perception. One of the claims I made is that body movement is not merely a reaction to hearing rhythms but that moving our bodies influences the way we hear rhythms; body movement is a part of the perceptual structure. Tapping your foot, e.g., affects the way you hear a given swing rhythm. (To musicians and phenomenologists, this is not an outlandish claim, but many analytic philosophers do not accept it.)
Interestingly, recent work by psychologists Jessica Phillips-Silver and Laurel J. Trainor provides experimental evidence that body movement influences rhythm perception. In their paper, "Hearing What the Body Feels: Auditory Encoding of Rhythmic Movement," they describe recent experimental findings to the effect that body movement affects subjects' perception of ambiguous rhythms.
This is their summary of the experiment. "We trained adults, while listening to an ambiguous rhythm with no accented beats, to bounce by bending their knees to interpret the rhythm either as a march or as a waltz. At test, adults identified as similar an auditory version of the rhythm pattern with accented strong beats that matched their previous bouncing experience in comparison with a version whose accents did not match" (Phillips-Silver and Trainor, p. 533; Cognition, 105, 2007). [thanks, Bill]
Whereas Phillips-Silver and Trainor are concerned with the effect of earlier body movement on later interpretation of rhythmic structure, my specific concern has been more qualitative, with the way we hear fine-grained, performed, rhythmic variations (timing nuances) while we move. Very briefly, I believe that hearing grooves (the feel of a rhythm as "leaning" or "pushing," e.g.) involves feeling, in the body, early or late notes as thwarted rhythmic expectations. Our experience of expectations of rhythmic regularities becomes deepened through body movement which is in accord with the regularities. When slightly early or late notes disrupt regularities—if we are moving—we experience the thwartings in our bodies, more qualitatively than if we had been perceiving in a detached manner.
