Some movements that musicians make are non-essential to their instrumental playing, yet express their intentions and interpretations of music’s structures. One such potential interpretation is the choice to emphasize short melodic groupings or to integrate these groupings into a phrase. This study aimed to characterize the nature of head motions associated with either interpretation by having cellists play two versions of a musical excerpt: 1) with short groupings specified, and 2) with long groupings specified. Cellists were filmed by two video cameras (front and right-side perspective) and the positions of their forehead and cheek were analyzed in their respective two-dimensional spaces. We hypothesized that the amount and frequency of movements would change according to the intended grouping. The results show that, overall, participants’ heads move more frequently when intending short groupings compared to long groupings. However, the extent of the change in motion varied across different sections of the excerpt. It appears that performers may invest more effort to emphasize the intended interpretation when a given local pitch structure more easily affords alternative interpretations. Our results illustrate that performers can embody melodic groupings based on intended interpretation.

when finger taps are synchronized with an isochronous click, it is known that tap-click asynchrony and its variability increase with the interonset interval (IOI). It remains unclear whether these results are due to the IOI or the intertap interval (ITI) duration. The present study examines how these two factors influence tapping performance by altering the tap-click ratio (i.e., 1: n tapping). It has been shown that holding the ITI constant while decreasing the IOI—so that extra clicks subdivide each tap—results in a reduction of tapping variability, described as a subdivision benefit (Repp, 2003). Two questions remain: Does asynchrony and variability increase with the ITI while holding the IOI constant? Does asynchrony decrease with the IOI while holding ITI constant? Using linear regression, both asynchrony and variability decreased with the IOI, with little additional effect of ITI. In contrast, when using ITI as a predictor, the contribution of IOI was significant, suggesting that IOI is the main determinant of tapping performance. In addition, an ANOVA revealed a disadvantage for 1:3 tapping, supporting a categorical distinction between duple and triple meters since 1: n tapping can engender the subjective feel of different metric structures.