The half-life of half-rhyme

Rhyme is such a constant feature in classical Chinese poetry that it is easily taken for granted. Before the compilation of rhyme books, there were no accepted standards for rhyming practice. Poets took advantage of this freedom to experiment with different rhyming patterns, such as imperfect rhymes between similar, but not identical, finals. In this paper the term "half-rhyme" is used to describe individual rhyme sequences which are irregular given contemporary conventions, and "lax rhyming" to describe a pattern of half-rhyme occurring frequently in a work. The intentional use of lax rhyming helps to explain the deviations from expected rhyme groups that we see in early medieval Chinese literature. In particular, it provides a better explanation for some of these deviations than past hypotheses involving dialect variation, as shown through analysis of Han rhyming practice. A proper recognition of half-rhyme can contribute to the interpretation of literary works, as in the "Qi chu chang" poems by Cao Cao, which are especially irregular in prosody, but do make extensive use of half-rhyme. Half-rhyme is by nature transient and imprecise, never codified in any poetic handbooks, so we may identify isolated examples but no universal patterns.