This study analyzes how the Akashi Plan was reformed in the 1950's from a core curriculum to one organized by subjects, with the purpose of clarifying the practical materials and characteristics of music education. The Akashi Plan was first made in 1949 based on the idea of a core curriculum. Then the reform of 1953 made the curriculum focus on personal achievement level. In the next reform in 1957, the curriculum plan became organized by subjects. Through this process, the materials and activities for music education changed as follows : 1) In the 1949 version, the materials were chosen according to the theme of core study for singing or other group activities such as concerts, but this style could not successfully improve music skills. 2) In the 1953 version, the materials focused on acquiring music skills and knowledge according to personal achievement level. 3) In the 1957 version, music class was taught based on the unit of music's subject and considering achievement level of music skills and knowledge.