Gayageum sanjo, the intangible cultural property No. 23, has a great educational value in terms of a musical-culture, social, and historical perspective. In the 2015 Revised Music Curriculum, a ‘music appreciation and criticism’ course was newly offered under the career choice curriculum, so a need for research on teaching-learning content for sanjo is raised. For this, the study aims to examine the Park, Sang-geun school gayageum sanjo of the Chungcheong area from a music historical and cultural context, thus providing instructional content for ‘music appreciation and criticism’ class. The Park, Sang-geun school gayageum sanjo of Chungcheongje was passed down from Park, Pal-gwae to Park, Sang-geun. It was designated as national intangible cultural property No.23 in 1968, and Sung, Geum-ryeon was recognized as a holder of the intangible cultural property. In 1977, however, the succession was cut off as the holder’s approval was lifted. One of the musical characteristics of the Park, Sang-geun school sanjo is the inclusion of gutgeori in its jangdan, but according to actual performances and literature, it is necessary to switch the name of the existing sanjo jangdan from ‘jungjungmori-gutgeori’ to ‘gutgeori-jungjungmori.’ Also, naedeureum in jinyang of the Park, Sang-geun sanjo is similar to that of other sanjos, but its cadence is quite different. Instead of ending in perfect cadence, it continues a melody with connecting cadence depending on modes and musical sentence. As described above, the instructional content for ‘music appreciation and criticism’ class is selected as follows, centering on the examination of the Park, Sang-geun school sanjo. In appreciation, ‘the origin and formative process of gayageum sanjo, regional sanjo, naedeureum and cadence patterns and jangdan structure of the Park, Sang-geun gayageum sanjo of Chungcheongje are selected as the instructional content in accordance with the curriculum guidelines. Students are instructed to understand that sanjo naturally occurred depending on the social, cultural, and historical background in the late Joseon period and was developed into various schools to finally reach a current form. They are also instructed to understand unique melodic expressions and jangdan structure presented in the Park, Sang-geun school gayageum sanjo of Chungcheongje. In criticism, recognition of values of the sanjo of Chungcheongje as an intangible cultural property and issues of preserving the intangible cultural property are selected as the instructional content. Teachers place emphasis on developing musical competencies that can help students interpret and evaluate various values ​​of the gayageum sanjo of Chungcheongdoje on the ground of critical thinking. They also have students to criticize preservation and transmission system of the sanjo, the intangible cultural property No. 23, thus having a significance of criticism as a professional. This study has implications for presenting the instructional content for ‘music appreciation and criticism’ under the career choice curriculum by examining the origins and formative process, historical and cultural background and musical characteristics of transmission genealogy in regard with the Park, Sang-geun school gayageum sanjo.