It is said to have begun as a tune from the western frontier that
唐玄宗 reworked and renamed, and legend has him first hearing it on a dream visit to the palace of the moon. In
白居易's
长恨歌 it marks the end of the golden age:
渔阳鼙鼓动地来，
惊破霓裳羽衣曲。 'War drums from Yuyang come shaking the earth and shatter the Rainbow Skirts dance', the outbreak of the An Lushan rebellion in 755. The music was later lost.
