Metre (poetry) of over some two-and-a-half millennia. Beginning with the earlier recorded forms: the Classic of Poetry tends toward couplets of four-character lines, grouped in rhymed quatrains; and, the Chuci follows this to some extent, but moves toward variations in line length. Han Dynasty poetry tended towards the variable line-length forms of the folk ballads and the Music Bureau yuefu. Jian'an poetry, Six Dynasties poetry, and Tang Dynasty poetry tend towards a poetic metre based on fixed-length lines of five, seven, (or, more rarely six) characters/verbal units tended to predominate, generally in couplet/quatrain-based forms, of various total verse lengths. The Song poetry
Triadic-line poetry Triadic-line poetry Triadic-line poetry or stepped line is a long line which "unfolds into three descending and indented parts". Created by William Carlos Williams, it was his "solution to the problem of modern verse" and later was also taken up by poets Charles Tomlinson and Thom Gunn. Williams referred to the prosody of triadic-line poetry as a "variable foot", a metrical device to resolve the conflict between form and freedom in verse. Each of the three staggered lines of the stanza should be thought of as one foot, the whole stanza becoming a trimeter line. Williams' collections "Journey to Love"