The purpose of the current study is to detect foreign elements during formation and development of Goryeo folk songs and investigate their meaning. Therefore, the study examined the origin of Tang music, transmission of China and the history of Goryeo's acception focusing on the role of Tang music on formation of Goryeo folk songs, and reviewed characteristics of Tang music, influence of Tang music on court feast culture of both countries, etc.
Examining the origin and transmission of Tang music through the Sui, Tang, Yuan and Ming Dynasties, Sui and Tang created court feast music using a lot of national music, especially music from the countries to the west of China and the mandolin. And this acception of foreign music became an opportunity of creation of classic literature. During the Song Dynasty, court feast music was expanded by importing foreign music like western music and foreign musical instruments like stringed instruments while succeeding feast music of the Sui and Tang Dynasties. Development of Daegok (Great Song), large-scaled art integrating songs and dancing, caused qualitative and quantitative change of classic literature. The court of the Yuan Dynasty actively received music and musical instruments of other races while succeeding feast music of the Sui, Tang, Song and Yuan Dynasties. At the same time, Sangok(a kind of song) and Japgeuk(a kind of play) were introduced. Like this, the fact that China tried to accept cultural assets of various races when they integrated many races and broad regions was a result of their efforts to enhance own cultural level.
Korea's imports of Tang music began from the King Munmu of the Silla Dynasty, and Silla's music and court feast were expanded while accepting Gochuiak(advocative music), feast music, and Tang's musical instruments like Bakpan, Daego, pipe, mandolin, etc. Imports of Tang music were very active during the Goryeo Dynasty. During the King Gwangjong, the Goryeo royal court was able to secure royal court dance and Sansa of Tang music as feast music through imports of Gyobangak and Saak, and expand own music using musical instruments like Banghyang, Tongso(a six-holed bamboo flute), Jeok, mandolin, Ajaeng, Janggo, Haegeum(a fiddle), etc. In addition, Tang music of the Goryeo contained western elements as well because Tang music was formed on the basis of western music. Therefore, there are traces of western music in <Yeonhwadae>, <Gamhwangeunryeong>, <Nangdosaryeong>, <Sagangwolman>, etc. Also Daegok and Sansa gave a lot of influences on formation of Goryeo folk songs.
Sokak Jeongjae includes more western traces than Sokakgasa, especially <Jeongeup> has foreign features in a sense that Mugo, a tool for dancing, is a foreign musical instrument and musical tone and melody of a mandolin, a western musical instrument, has Tibet's Rolo rhythm. As for <Dongdong>, Abak, a tool for dancing, originated from the west and Changsa(lyrics) originated from Donhwanggok, while as for <Muae>, Horo, a tool for dancing, originated from the west and a record specifies that it is from the west. Therefore, those three works have outstanding exotic elements beyond China.
In addition, it is possible to say that Sokakgasa such as <Cheoyongga>, <Ssanghwajeom>, <Cheongsanbyeolgok>, <Isanggok>, <Gasiri>, etc. were influenced from foreign countries in consisting the whole pieces or part of them in terms of origin, music, poetic word, mixture of multiple languages and rhetoric aspects. They have exotic features beyond China because of the following reasons. With respect to <Cheoyongga>, there is a possibility that Cheoyong is a Islam person and its dance is similar to western dance; in <Ssanghwajeom>, use of poetic words, the same style as Japgeuk of the Yuan Dynasty influenced by the west, and Janggu-type music with foreign style; in <Cheongsanbyeolgok>, use of Haegeum, a western musical instrument, the deer symbol is associated with Ghazal, a romantic love poem created in the middle Asia; four phases of <Isanggok> can be interpreted into Sanskrit; in <Gasiri>, use of a refrain originated from the tradition of Daegok of Tang songs.
As stated above, Tang music of the Goryeo Dynasty not only was evidence presenting that musical exchange of Asia included the Goryeo Dynasty, but also prepared an opportunity to improve music of the Goryeo Dynasty to a world-class level. As a result, Goryeo Sokyo, luxurious masterpiece of Asian royal court feast art in the Middle Ages, could be created.