What is the historical background of the emergence and development of dance in Liao Dynasty?

Liao State, originally a regime established in Northeast Asia in 906 by a Khitan in the ancient Donghu Cong, was founded as Khitan in the first year of Shenshu (9 16), and was also called Liao because it originated in the Liaohe River Basin. Liao Taizong was officially named Liao in the first year of Huitong (938). At this time, the Song Dynasty had lost its ability to control the surrounding areas. The Khitan nationality took the opportunity to develop in the Yellow River area south of the Great Wall, and adopted preferential policies for Han talents and those skilled in crafts. Confronted with Mongolian tribes in the desert in the north, managed Xixia and other countries, destroyed the Bohai Sea, conquered the northern part of the Korean Peninsula, combed the east-west traffic, and won sixteen states, which developed into a great empire with "the sea in the east, quicksand in the west, desert in the north, and hosting Wan Li". The Liao State once took Huanglinfu (now Balinzuoqi, Inner Mongolia) as its capital, and established a "North-South" system, which took charge of the Khitan affairs in the north and the Han land in the south, and set up three provinces and six departments in imitation of the Tang and Five Dynasties. When Liao State and Song Ting finally signed the Alliance of Mending Heaven, their lax military defense left room for the Nuzhen who lived together in the north, and was finally destroyed by the Jin people.