In this study, the effect music assisted instruction on students' exam scores taken from triangle subject was investigated. The research was made with 177 of the freshmen from 4 different classes in Buca Faculty of Education, and the department of Elementary Mathematics Teaching in 2011-2012 in fall semester. In this study, experimental model with pre-and post-test control group was used. For this purpose, two experimental and two control group were formed. Music assisted instruction by making one of the experimental groups listen to Classical Music and one listen to Turkish Art Music just before presenting the triangles in geometry class during five weeks and non assisted instruction were applied to the control groups in presenting triangles in geometry lesson. "The achievement test of triangles" was used as data collection tool. As a result of the research, it was determined that music assisted instruction was effective on student success in triangles comparing to traditional instruction; however, no significant difference was found between experimental groups listened to Classical and Turkish Art music.