 Dances became absorbed into opera, and dance became an essential component to be mastered by opera performers.The integration of dance into opera is particularly evident in kunqu opera such as the Ming dynasty piece "The Peony Pavilion" whereby each phrase of singing may be accompanied by a dance movement, and the opera is interspersed with song-and-dance pieces.Dances such as "Dance Judgement" (舞判, also called the Dance of Zhong Kui, 跳鐘馗) became opera pieces in the Ming dynasty, and dances of the Song dynasty such as Flapping the Flag (撲旗子) later became part of Chinese opera.