History of Liao
The term "guoyue" appeared in various ancient texts and had various different meanings before the 20th century. It was used as early as the Sui-Tang period to refer to court music or "yayue". In the "Music Record" section of "History of Liao", it was used to distinguish the music of the Khitan rulers from that of the Han Chinese. During the Qing Dynasty it was used to refer to the kind of ceremonial court repertoire that was seen as a representation of China.