Sankyoku (sanqu in Chinese) (散曲)
Sankyoku is a kind of music (qu) and a form of poetry in the spoken language and is also literature of songs and ballads. It flourished during the Yuan, Ming and Qing Dynasties.
There are two kinds; one is 'Santo' (the abbreviation of Sankyoku-tosu, also simply called Tosu [taoshu in Chinese]) and the other is 'Shorei' ([xiaoling in Chinese] different from Shorei of Ci, another type of literature)
'Santo' is a suite form of poetry composed of the same scales (gongdiao in Chinese), in which major and minor are irregular and a single rhyme is used through the poem. It is the same as the lyrics in zaju (Chinese classical theatrical play) in nature, and so oftentimes a writer wrote lyrics for both. Shorei' are short and independent melodies but possible to be composed. There is also another kind, 'taikakyoku' (daiquoqu in Chinese), composed of two or three melodies, but it is categorized as part of shorei.
Sankyoku (sanqu in Chinese) flourished along with zakkyoku (ｚaju in Chinese) in the Yuan Dynasty, therefore they are called genkyoku (yuanqu in Chinese) in general.
Works as 'Majie' by Ma Zhiyuan, 'Niu Suyuan' by Yao Shouzhong, 'Gaozu Huanxiang' by Sui Jingchen and 'Shanggao jiansi' by Liu Zhi are famous. In many cases, the same writer writes both sankyoku and zakkyoku, but some writers like Zhang Kejiu and Guan Yunshi wrote only sankyoku.