The experiment reported in this article investigated the assumption that visual movement plays a role in musician-to-audience communication in marimba performance. Body movement is of particular relevance here as the expressive capabilities of the marimba are relatively restricted, and the movements required to play it are visible. Twenty-four musically trained and 24 musically untrained observers rated auditory-only and auditory-visual presentations of 20th-century solo marimba excerpts for perceived "expressiveness" and "interest." Performances were given by a male and a female professional musician in "projected" (public performance expression) and "deadpan" (minimized expressive features) performance manners. As hypothesized, higher ratings were recorded in response to projected performances than to deadpan. The hypothesized interaction between modality and performance manner was observed. Musically trained participants recorded higher ratings than musically untrained observers, upholding the final hypothesis. Expressive body movement plays an important role in the communication between marimba performer and audience--a role relevant for both performers and educators. (Contains 2 figures and 1 note.)