沈寵綏 度曲須知 絃索辨訛 陰出陽收 清音濁流 體兼南北 戲曲正音 Shen Chong-Sui Du qu xu zhi Xian suo bian e Yin chu yang shou Qing yin zhuo liu A genre cooperating the Northern and Southern operas The standard sounds of traditional Chinese operas The North succeeds Zhong yuan yin yun and the South follows Hong wu zheng yun