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
Metre (poetry) metrical patterns are made of long and short syllables, much as in Classical Greek, Latin and Arabic. "Anceps" positions in the line, however, that is places where either a long or short syllable can be used (marked "x" in the schemes below), are not found in Persian verse except in some metres at the beginning of a line. Persian poetry is written in couplets, with each half-line (hemistich) being 10-14 syllables long. Except in the ruba'i (quatrain), where either of two very similar metres may be used, the same metre is used for every line in the poem. Rhyme is