Changes

'Causal Tunes' ( 散曲 Sanqu ), also known as 'Pure Tunes' ( 清曲 Qingqu ) and yuefu ( 樂府 Yuefu ), consist of Little Tunes ( 小令 Xiaoling ) and Serial Tunes ( 套曲 Taoqu ). Little Tunes refer to single tunes, which include Transitional Tunes ( 帶過曲 Daiguo Qu ), which comprise less than three tunes from a same musical unit sharing the same rhyme, and Repetitive Little Tunes ( 重頭小令 Chongtou Xiaoling ), which consist of a few Little Tunes with the same contents and structure, but having different rhymes. In contrast, Serial Tunes include three elements: the same rhyme throughout; a concluding tune; and at least two Single Tunes out of the same musical unit. Because of their considerable length, Serial Tunes are normally used to target complex themes by either narrative or lyrical skills.