Rhyme generally requires a unified number of words in a poem, and each poem will be divided into five or seven sentences according to the number of words, which is called "five laws" and "seven laws" for short. Ordinary metrical poems generally stipulate that each poem has only 8 sentences.
Once more than eight sentences reach 10, it is called "exclusion law" or "long law". Rhyme also needs a flat set, and the rhythm is harmonious enough. Rhyme prevailed in the Tang Dynasty, on an equal footing with Song Ci, Yuan Qu and Ming and Qing novels.
Metric poems are generally eight sentences each, and more than eight sentences are called parallel sentences or long sentences. The number of words in a metrical poem sentence is uniform, and each sentence has five or seven words, which are called five-character metrical poem and seven-character metrical poem respectively. The five laws stipulate that every sentence has five words, and the first word is forty words; The seven laws stipulate that each sentence has seven words and the whole sentence has fifty-six words. There are also six-character sentences, all of which begin with 48 characters. They are called six-character poems, and there are few handed down works.
The rhythm of metrical poems:
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 sentence of rhyme, which is called "borrowing rhyme"
Rhyme also requires the whole poem to rhyme, that is, the ending rhymes, and the middle rhyme is not allowed. 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.
In quatrains, the requirements of archaic quatrains and metrical quatrains are different, among which metrical quatrains, like metrical poems, pay attention to fluency and strictness according to the characteristics of metrical sentences. Although ancient quatrains rhyme, they are relatively free, or they are written by poets who don't want to be bound by meter.