Metric poems originated from Shen Yue and other new-style poems that emphasized the antithesis of metrical poems in the Southern Dynasties, and were further developed and stereotyped by Shen Quanqi and Song Wenzhi in the early Tang Dynasty, which prevailed in the Tang and Song Dynasties. Rhyme has strict rules in word, rhyme, even tone and antithesis.
The rhyme feet are usually flat and must be rhymed according to the words in the rhyme book. In principle, only the original rhyme can be used, not the adjacent rhyme; Even if it is a little looser, the adjacent rhyme can only use the first rhyme, which is called "borrowing rhyme" and also requires a rhyme in the whole poem, that is, a rhyme to the end, and no rhyme change is allowed in the middle. The second, fourth, sixth and eighth sentences rhyme, and the first sentence can be taken or not. The five laws take the first sentence as a positive example and rhyme as an example; The seven laws take the rhyme of the first sentence as a positive example, and the non-rhyme as a variant.
Extended data:
In a pair of couplets, the total number of flat and even words is equal. If "135" that can be handled flexibly should use flat-voiced words instead of flat-voiced words (or use flat-voiced words instead of flat-voiced words), then it is often necessary to change flat-voiced words into flat-voiced words (or change flat-voiced words into flat-voiced words) at an appropriate position in this sentence or dialogue to maintain the number of flat-voiced words in a couplet.
The first characteristic of duality is that syntax should be the same. For example, the first sentence of the first couplet of One Night Abroad has no predicate, and the second sentence is relatively meaningless. The sentence pattern of the upper sentence of the couplet is "subject-predicate-object", and so is the next sentence. The neck couplet uses the same sentence pattern.
The second characteristic of duality is that you can't use the same words to oppose each other. The antithesis like "people have joys and sorrows, and the moon has ups and downs" is allowed in lyrics and songs, but never allowed in modern poetry. In fact, unless it is necessary for rhetoric, the same words must be avoided in modern poetry.