Ensemble musicians coordinate their actions with remarkable precision. The ensemble cohesion that results is predicated upon group members sharing a common goal; a unified concept of the ideal sound. The current chapter reviews research addressing three cognitive processes that enable individuals to realize such shared goals while engaged in musical joint action. The first process is auditory imagery; specifically, anticipating one's own sounds and the sounds produced by other performers. The second process, prioritized integrative attention, involves dividing attention between one's own actions (high priority) and those of others (lower priority) while monitoring the overall, integrated ensemble sound. The third process relates to adaptive timing, i.e., adjusting the timing of one's movements in order to maintain synchrony in the face of tempo changes and other, often unpredictable, events. The way in which these processes interact to determine ensemble coordination is discussed.