The purpose of this study was to examine the effects of three practice conditions on beginning band instrumentalists’ performance of a short musical selection. Fifty- nine sixth grade beginning band students were randomly assigned to either a physical practice, mental practice, or no practice (control) treatment. A pre-test score was obtained by having each subject sightread selection #2 from Form A of the Watkins/Farnum Performance Scale. Subjects were then given instructions according to the practice condition to which they had been assigned. After a three minute practice session, subjects were asked to perform selection #2 from Form B of the Watkins/Farnum Performance Scale to obtain a post-test score. All of the performances were tape recorded and scored on the basis of correct pitches and rhythm patterns by three music teachers. Mean scores were analyzed using a one-way ANCOVA and a Scheffe’ Test. The results of the study indicated that students in the physical practice condition scored significantly higher than those in the control group. Mental practice was not significantly different from either the physical practice or no practice (control) groups. / Master of Science