Poetry have challenged the traditional definitions of the sonnet form, rendering entire sequences of "sonnets" that often lack rhyme, a clear logical progression, or even a consistent count of fourteen lines. "Shi" () Is the main type of Classical Chinese poetry. Within this form of poetry the most important variations are "folk song" styled verse ("yuefu"), "old style" verse ("gushi"), "modern style" verse ("jintishi"). In all cases, rhyming is obligatory. The Yuefu is a folk ballad or a poem written in the folk ballad style, and the number of lines and the length of the lines could be irregular. For the
Sonnet 57 type of poetic metre based on five pairs of metrically weak/strong syllabic positions. The sixth line exemplifies a regular iambic pentameter: The first line exemplifies an initial reversal and (optionally) a mid-line reversal: Rhian Williams asserts, "In literary value Shakespeare's sonnets are notably unequal. Many reach levels of lyric melody and meditative energy that are hardly to be matched elsewhere in poetry". His 57th sonnet is such a one and epitomises Shakespeare's signature sonnet structure as it conveys the influences of the 14th-century poet, Petrarch, and showcases again Shakespeare's talent. In fact, Danijela Kambasković-Sawers generalises, "The sonnet sequence genre constructs