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
Poetry calligraphy. These basic units of poetic form are often combined into larger structures, called "poetic forms" or poetic modes (see following section), as in the sonnet or haiku. Poetry is often separated into lines on a page. These lines may be based on the number of metrical feet, or may emphasize a rhyming pattern at the ends of lines. Lines may serve other functions, particularly where the poem is not written in a formal metrical pattern. Lines can separate, compare or contrast thoughts expressed in different units, or can highlight a change in tone. See the article on line breaks