Tracking an Imposed Beat within a Metrical Grid

RHYTHMIC STRUCTURE OFTEN FAVORS a particular beat that is marked by frequent tone onsets and grouping accents. Using rhythms similar to those of Povel and Essens (1985), we asked musically trained participants to tap on physically or mentally imposed beats that either coincided with the favored beat or were phase-shifted relative to it. Surprisingly, tapping was equally stable. Actually, variability tended to be lowest when the imposed beat was in anti-phase with the favored beat; however, this tendency was reversed when participants were instructed to tap in anti-phase with the beat. These results demonstrate that precise on-beat synchronization with different imposed beats can be achieved by locking into the metrical grid defined by a rhythm's basic pulse. The favored beat provides the most stable reference for off-beat tapping but not necessarily for onbeat tapping, which relies to a greater extent on intervening rhythm tones as temporal references.