The purpose of this study was to compare the relative effectiveness of three "mental" practice strategies: 1) silent, motionless mental practice, 2) singing/vocalizing, and 3) playing "air cello." Traditional physical practice was used as a control condition. Twelve collegiate-level cellists participated in the experiment, from which improvement scores for tonal accuracy, rhythmic accuracy, and expressive qualities of the music were calculated. Results showed that mean improvement scores were highest for physical practice and lowest for singing/vocalizing. Although the improvement score for silent, motionless mental practice was not as high as that for physical practice, the difference between these scores was not statistically significant, suggesting that silent, motionless mental practice may be nearly as effective as physical practice. Differences between the three types of mental practice were also not statistically significant, perhaps due in part to subjects' mixing of practice strategies. Post-experiment questionnaires were used to examine participants' past experience with alternative practice techniques and their perceptions of the effectiveness of mental practice. (Contains 3 figures.)