Poetry belongs to verse. Metric is one of the forms of poetry creation, which began to rise in the Tang Dynasty. Metric poetry is unique to China's ancient poetry, and it is a rule that poets should abide by in writing format and rhythm, such as leveling, antithesis, rhyming, sticking, difficult to exist and so on. Among them, level tone is an important basic part of metrical poetry writing, and one of its characteristics is that every sentence has a level tone provision. To learn to write metrical poems, we must master basic knowledge such as leveling. If we don't follow or understand the rules of writing metrical poems, the poems we write can't be called metrical poems.

What is the reason why ancient poetry emphasizes simplicity? Flat tone is the tone of words used when writing metrical poems, and it is also a special term of metrical poems. "Flat" means straight, and "flat" means uneven. The theory of level tone is a kind of temperament that the ancients explored and summarized in the long-term practice of poetry creation. Poems and sentences written in a flat, flat, staggered and opposite way can be read from top to bottom, cadenced and catchy, and the sound can be harmonious and pleasant, with the effect of beautiful rhythm. The unique aesthetic feeling of China's ancient poems is reflected by the level of sentences. The beauty of antithesis and phonology of metrical poems is the crystallization of ancient wisdom.

Flat tone is based on the four tones of Chinese. Four tones are the classification of Chinese four tones. The so-called tone refers to the level, length and rise and fall of the sound. According to the research of Mr. Wang Li, a famous linguist, 1) four tones are divided into two categories, and "ping" refers to the ping among the four tones; "Wrong" refers to the mistake of four tones, including the upper, lower and middle tones. Flat tone is flat tone, rising tone is rising tone, falling tone is falling tone, entering tone is short tone, rising tone, falling tone and entering tone is continuous tone. 2) Now the entering tone of Putonghua has disappeared, which belongs to two tones: the rising tone in Cuo and the rising tone in Pingping. The four tones of Putonghua are: flat tone, rising tone, rising tone and falling tone. Among the four tones of Putonghua, Yin Ping and Yang Ping are flat tones; Both rising and falling tones are slurs. Many changes have taken place in modern sounds and ancient sounds. People often find this difference when reading ancient poems. If you don't understand this situation, you will mistakenly think that the ancients wrote flat lines and rhymes wrong. Pronunciation and intonation change slowly with the development of society.

There are three types of ancient poems in China: ancient poems, modern poems and variant poems. Poems written in accordance with metrical patterns after the Tang Dynasty are called modern poems, including quatrains, metrical poems and parallel poems. When writing metrical poems, we must follow the basic formats such as flat and flat. At present, it is not advisable for some people to simply deny the format of metrical poems such as Pingping on the grounds of innovation and on the pretext of "leveling without damaging the meaning". Many reasons are actually a reflection of lazy mentality. The musical beauty of "meaning" expressed in China's ancient poems is revealed through melody, which has become a part of our life. (Yao)