laban movement analysis, specifically effort-shape analysis, is offered as a system to study musicians' bodily expression. It proposes others' intentions are manifest in expressive bodily activity and understood through shared embodied processes. The present investigation evaluates whether the basic components of Laban analysis are reflected in perceptual judgments of recorded performances and, specifically, evaluates interjudge reliability for effort-shape analysis. Sixteen audio-visual excerpts of marimba pieces performed by two professional solo marimbists' (female and male) served as stimuli. Effort-shape analyses and interjudge reliability thereof were assessed through three different tasks: 1) verification task, 2) independent analysis task, 3) signal detection yes/no task. Professional musicians — two percussionists, a violinist, and a French hornist — acted as participants. High interjudge reliability was observed for transformation drive and shape components, but less so for basic effort action components. Mixed interjudge reliability results for basic effort actions, and differences between frequency observations, point to differences in participant's embodied expertise, task implementation, and training issues. Effort-shape analysis has potential to drive comparative and predictive research into musicians' bodily expression. Effort-shape provides a fine-grain temporal analysis of ecologically valid performance sequences.