The Interchange of Dance & Music Koryo and Song Times and the Historic TrendSook-Kyung Shim, Doc.Professor of continuous educationBeijing Dance AcademyThe Korean and Chinese relationship during the Ko-Ryo (918-1392) and Song (960-1279) eras came to a special situation, which was different than what has occurred in the previous; the most important reason for this was the foundation and extending power of Yo (916-1125) and Geum Dynasty (1115-1234) that had been established in Yo- Dong province. Due to the constant threats and invasions to Ko-Ryo and Song, both countries maintained their intimate relationship to keep the political purpose of restraining and balancing the Yo and the Geum. The Dae Sung Ak and Dang Ak Jung Jae that is transferred to Ko-Ryo from Song in this time are the product of Song?s political purpose and Ko-Ryo?s cultural purpose.It is certain that the time of Dang Ak Jung Jae?s transfer to Ko-Ryo had occurred for about 100 years, since the two countries have resumed in the end of north Song, the year 1071, until it was completely extinct again in the south Song?s earlier times. Cho Young and Jin Kyung, who first introduced Dang Ak Jung Jae to Ko-Ryo, are presumed as the Kyo Bang musician professors dispatched from Song, after the two countries? interchanged resumption.The interchange of dance and music between Ko-Ryo and Song had been made up in two ways: first, as Ko-Ryo requested, to send music professors, and hand over techniques to them. Second was to send artists of music and dance to Song from Ko-Ryo Dynasty to be studied and to be trained. As Song?s Kyo Bang musician professors, who were dispatched to Ko-Ryo, stayed there for few years or for a long time, they handed down the arts to Ko-Ryo?s artists. Belonging to Ko-Ryo?s Royal Dancing Institute, they received wages as they passed down the art of dance and music of Song Dynasty.