Ci -poetry, serving as the predominant form of verse in the Tang and Song dynasties, is characterized by lines of unequal length with prescribed rhyme schemes and tonal patterns, each bearing the name of a musical air. There exist three different explanations for the origin of  ci -poetry. It may have evolved from ancient  yuefu  (a folk song style poetic form prevalent in the Han Dynasty), Tang poetry, or  huyue  (music of ethnic groups from the northern, northwestern, and western regions in ancient times).  Huyue  was popularized in the Central Plains (comprising the middle and lower reaches of the Yellow River) since the Northern Dynasties (386–581). The poets of the Tang Dynasty created a new form of verse by filling in new characters or words to a given  huyue  tune. Accordingly,  ci -poetry is also called "word-filling poetry." On the other hand, its varying numbers of characters earned it another name, "lines of irregular lengths."

 Ci -poetry was fully developed during the Song Dynasty (960–1279). There were two schools of  ci  poets in this period, the best-known representatives of which were Su Shi and Xin Qiji from the  haofang  (bold and unconstrained) school, and Li Qingzhao and Liu Yong from the  wanyue  (graceful and restrained) school. Each  ci  poem has a  cipai  (tune pattern), including  Yijianmei  ( A Twig of Plum Blossoms ),  Pusaman  ( Buddhist Dancers ), and numerous others. Each  ci  poem is composed with a unique tonal pattern, rhythm, and rhyme scheme.  Ci -poetry can be classified into short lyrics, medium-length tunes, and long tunes according to the length of its lines. Based on the number of segmentations included,  ci -poetry is also divided into single-stanza verse, double-stanza verse, triple-stanza verse, and four-stanza verse.