a genre of classical Chinese poetry. The tz’u evolved from folk-song tradition in the second half of the eighth century, although some sources indicate that individual poems in the genre appeared in the seventh century. The tz’u reached its peak in the 11th and 12th centuries in the works of Liu Yung, Ou-yang Hsiu, Su Shih, Li Ch’ing-chao, Lu Yu, and Hsin Ch’i-chi.

Verses in the tz’u genre were originally written as the texts for airs to be sung to one of more than 800 melodies. For this reason, tz’u poems are subdivided into distinctive cycles. In each cycle the melody determines the meter, alternation of tones, combination of lines, and rhyme. The rhyme in the tz’u, as opposed to that used in the shih, is not regulated by any specific rhyme scheme. The tz’u is basically a lyrical poem describing nature or intimate emotions; however, Su Shih, Hsin Ch’i-chi, and other poets also introduced philosophical and patriotic themes.