The purpose of this study was to examine the differences in teacher behaviors between classes with high diagnostic results of learning group functioning (upper group:3classes)and classes without high diagnostic results (middle group:3classes)in upper elementary school instrumental exercise classes (6classes). The results showed that the teachers in the upper group used creative questions,positive feedback (skill and cognitive), and encouragement significantly more often than those in the middle group. In addition, the results of the class observations showed that the upper group had a common place for observational learning in all classes, and thoughtful learning was developed in the whole class. It is thought that these teacher behaviors enhanced the learning group function in the learning of the instrumental exercise, which is an individual event.