Ancient poetry is divided into three parts according to the rhythm.

The rhythm and meter of poetry can be divided into metrical poems and quatrains. 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. Metric poems, including metrical poems and quatrains, are called modern poems or modern poems. The ancients called it that, and we followed suit. Although it is actually very old, it originated from Qi Liang in the Southern and Northern Dynasties and matured in the early Tang Dynasty. Poems before the Tang Dynasty, except the so-called "Qi Liang Style" and Chu Ci, are all called ancient styles. Poetry that does not conform to the modern style after the Tang Dynasty is also called ancient style.