The conductor of a large instrumental ensemble is constantly confronted with the task of detecting and correcting rhythm and pitch performance errors in daily rehearsals. The purpose of this investigation was to design a computer-assisted instruction program for error detection skills development and then evaluate this program's effectiveness in training beginning conductors to identify rhythm and pitch errors within 2-, 3-, 4-, and 5-voice synthesized music excerpts from the existing band literature. The transfer of error detection skills from synthesized to acoustic sounds also was explored indirectly by virtue of utilizing taped excerpts from wind band performances to assess error detection skills.Subjects (N=24) in this study were drawn from the pool of undergraduate instrumental music education majors at Ball State University and were randomly assigned to control treatment groups prior to the administration of the Acoustic Error Detection Skills Inventory. Following this pretest, the treatment group used the Computer Error Detection Skills Program for approximately eight hours during an eight week treatment period. At the end of the treatment period, and control and treatment groups were administered the Acoustic Error Detection Skills Inventory posttest.The data were analyzed using a series of one-way, repeated measures analyses of variance (ANOVA) to assess pretest to posttest changes in subjects' scores on the Acoustic Error Detection Skills Inventory. Composite scores (reflecting general skill in error detection) improved significantly for the treatment group (p = .007), while the pretest to posttest gain for the control group was not statistically significant (p = .232). These results suggest that the Computer Error Detection Skills Program was effective in enhancing subjects' rhythm and pitch error detection skills and the viability of using synthesized sound sources for training was confirmed.The following recommendations were made: (1) Jazz directors need to do more listening to jazz music, (2) band directors who direct jazz programs should join IAJE, (3) jazz ensembles shouldtheir own improvisational skills, and rehearse in the fall, (4) jazz ensemble directors should develop (5) jazz ensemble directors should have their students sing their parts during rehearsals for increased learning efficiency and retention. / Human Performance Laboratory