The following is Baidu Encyclopedia's introduction to beats and rhythms for your reference. You can search by yourself.
Rhythm refers to phonology and rhythm. Refers to the flat pattern and rhyme rules in poetry. Extend to the rhythm of sound. Biography of Yuan Zhen in the Old Tang Dynasty: "Deep thinking, close words, new rhythm, no difference between right and wrong, and boundless style." Ye Shengtao's "Tour Three Lakes": "Listening to the lake waves lapping on the shore is quite monotonous, but it has rhythm."
The rhythm of poetry includes three aspects: First, the level tone was first put forward by Shen Yue in the Northern and Southern Dynasties, and it was widely used in metrical poetry after the prosperous Tang Dynasty, mainly focusing on the coordination between level tone and level tone. The second is duality. In verse, especially in metrical poems, the requirement of duality is strict. There are generally sentence pairs in poetry, and there are also many sentence pairs and paragraph pairs in fu and eight-part essay. The third is rhyme, which means that rhyming words regularly appear in appropriate places (usually pause places). These three aspects all come from the characteristics of Chinese pronunciation, that is, monosyllabic morphemes are dominant and have tones. When writing poems, especially metrical poems, the use of parallelism, duality and rhyme is good and natural, which can enhance the sense of music and present the beauty of rhythm; Poor use and excessive use will give people a feeling of thankless, and even hurt the meaning with words. Parallel prose from the Six Dynasties to the early Tang Dynasty is an obvious example. This is the basic skill that every poetry lover must master.
Metric refers to a series of unique rules in China's ancient poems, which should be followed in terms of format and rhythm. China's ancient modern poems have strict metrical requirements, while others, such as ancient poems, modern poems and Europeanized poems, have no clear and strict metrical requirements.
Generally speaking, there are four elements in the metrical form of poetry: rhyme, flatness, duality and number of words. Among them, rhythmic poetry is the most strict, and all elements must be satisfied. Quatrains, words and Sanqu in modern poetry generally do not need confrontation. Classical poetry is relatively loose, generally only the concept of loose rhyme.
There are three main differences between ancient poetry and metrical poetry: syntax, phonology and parallelism.
Grammar:
The number of words in each sentence in ancient style is uncertain, including four words, five words, six words, seven words and even miscellaneous words (irregular sentences), and the number of sentences in each song is also uncertain, ranging from two to dozens to hundreds. There are only five words and seven sentences in modern poetry, eight in metrical poetry, four in quatrains and more than eight in quatrains, which is also called long-style poetry.
Rhyme:
Antique can use one rhyme or two or more rhymes for each song, and it is allowed to change rhymes; Each song can only use one rhyme, and even the arrangement of dozens of sentences cannot be changed. Antique can rhyme in even sentences, or even sentences can rhyme in odd sentences. The near aspect rhymes only in even sentences, except for the first sentence, which rhymes with a flat voice and does not rhyme. Five words don't gamble more, seven words gamble more), and the rest of the odd sentences don't rhyme; Antique can rhyme smoothly; Close to the body only requires flat rhyming.
Modern people can of course write modern poems with modern rhymes. If we want to use Pingyunshui according to tradition, we must pay attention to the differences between ancient and modern sounds, especially when reading ancient poems. These differences can sometimes be distinguished by dialects, but they are not necessarily reliable, so we should read more and recite more.
Flat:
The biggest difference between ancient style and modern style is that ancient style does not pay attention to flatness, while modern style pays attention to flatness. After the Tang dynasty, the ancient style also pays attention to flatness, but it is irregular and can be ignored.
note:
Any place that violates the taboo of metrical rules can be considered as a violation of the law, not just a violation of the rhythm. Violation of rhythm is of course more obvious.
For metrical poems, the number of words and sentences is inconsistent, misaligned, non-cohesive, non-rhyming, non-rhyming, non-repetition, non-loneliness and inequality.
For words, if you don't fill in the words according to the spectrum, all the outrageous things are out of the law.
However, the fact that a poem or a word comes out of the law does not prevent it from being a good modern poem or a good writing style.