The potential of using the Apple II+ microcomputer with an ALF products music software system (nine voice) for computer-assisted instruction in composition was examined. Two boys, 8 and 10 years of age, served as subjects. Naturalistic observations were made as the children participated in a 10-session program that consisted of composition activities, such as adding harmony and writing rounds, and related activities, including listening tasks. Most of the composition activities, particularly the round or canon, were found to be useful vehicles for teaching both composition and other topics, such as music fundamentals. There were some differences in the nature of the subjects' compositions and in their approaches to the tasks. Although one subject preferred a traditional orientation to the ALF program and the other had less conservative musical preferences, the program accommodated these individual differences. Moreover, the interest displayed by both subjects extended beyond the instructional sessions. Teacher characteristics, such as teaching skills and musical background, were found to be of critical importance for the success or failure of the microcomputer-based approach to music instruction. It was concluded that the ALF music system could be used to advantage on an individual basis in initiating interest in composition. Limitations of the program and the system are pointed out. (Author/RH)