The present study aims to contribute to the understanding of the effects of music education, in particular music composition as a classroom activity for fifth- and sixth-graders. The intervention (experimental condition) focused on a three-step-model for music composition, based on the Cultural Historical Activity Theory of education, and has been compared with a teacher-centered approach mainly based on students' reproduction of music (control condition). Results indicated that after the six-month intervention period, students in the experimental group were more engaged in music education compared to students in the control group. The research did not show a statistical difference in learning outcomes with regard to intelligence, academic achievement and music achievement, although the students of the experimental group performed better with regard to reading comprehension than their counterparts in the control group. The authors conclude that music composition as a classroom activity is feasible and useful in elementary schools.