Good music aptitude tests can help discover talented students and develop their musical potential, and improve music education by finding the weak and strong points of students. Especially Korean students need a music aptitude test that can measure both Western music aptitude and Korean music aptitude. In this study, we have developed a music aptitude test for the 5th to 9th grade students. This study has been conducted from August 1996 to August 1997. The subject of this study consists of the 5th and 6th grade students from three elementary schools in Seoul and Taegu, and the 7th and 8th grade students from three junior high schools in Taegu and Kyungbook. They are all 1711 in number. Our aptitude test called HSMAT has been developed through five times of pilot studies, and was administered in July 1997. 783 students from 6 schools participated in pilot studies. HSMAT consists of rhythm and tonal subtests. In the rhythm subtest, students are required to say same or different after listening to pairs of rhythm patterns without pitch. In the tonal subtest, students are required to say same or different after listening to pairs of 5-note tonal patterns without rhythm. The rhythm test items use 3/4, 4/4, 12/8 meters. The tonal test items are developed by considering the direction and shape of melodies. The 30-item HSMAT was first developed. But both its reliability and validity were not satisfactory. The rhythm test reliability in the 30-item HSMAT was .42. The tonal test reliability in the 30-item HSMAT was .75. Hence, 20 items good in item validity were chosen from each subtest, and the 20-item HSMAT was administered. The rhythm reliability in the 20-item HSMAT was .52 and the tonal test reliability in the 20-item HSMAT was .77. The item difficulties of the 20-item HSMAT are 66 in rhythm test and 57 in tonal test. It indicates that the tests are difficult for the students. To apply HSMAT, the test items need to be revised, especially in rhythm subtest. Especially they need to be made easier. An interesting point was observed : Those items whose answers are same are better in item validity than those items whose answers are difficult . For example, in the 30-item tonal subtest, among the 20 good items, the 19 items are those whose answers are same . To find out why items whose answers are same are good requires a further study. To evaluate the applicability of HSMAT, a validity study is needed. A correlation study with other standardized tests is also needed. Studies for the correlation HSMAT and music achievement and predictive validity are needed.