Ch’angguk is a Korean folk opera. The term Changguk is composed of two words, Ch’ang and guk. The former refers to a type of song called pansori. And the latter refers to ‘play’ or ‘drama’. Therefore Ch’angguk could be called a pansori drama. Pansori is a traditional Korean folk music and to perform pansori on the stage as a form of drama is a distinguishing characteristic of Korean culture. In other words, Changguk is a musical drama rooted in a musical tradition of Korea. In this respect, it can be compared to the Japanese Kabuki or the Chinese Peking opera. One can be qualified as a singer/actor in Changguk only when one masters pansori through special practice. The number of main characters in Changguk consisting of heroes/heroines and supporting actors/actresses is about 20-30, although the exact number varies drama by drama. It is also possible for more supporting casts to participate in a drama, depending on its nature. Music is played by a Korean classical music orchestra consisting of 30-50 members playing traditional Korean musical instruments. It may be that there are many dancing crews needed, if required by the composition of the drama. The works most frequently performed are Chunhayng-ga, Simchong-ga, Hungbo-ga, Sugung-ga, and so on, which are passed down from generation to generation as pansori.