Poets' names, dynasties and background of Long Songs, Seven Steps Poems and Out of the City.

Long Songs is a folk song of Yuefu in Han Dynasty, and its author is unknown. This poem begins with "Sunflowers in the Garden", and then the water flows to the sea, indicating that time is like running water, which is gone forever. Finally, it persuades people to cherish youth, work hard, and don't wait until they are old to regret it.

Seven Steps Poetry was written by Cao Zhi, a poet of Wei State in the Three Kingdoms period. According to ancient records, Cao Cao's second son Cao Pi (that is, Wei Wendi) was jealous of his younger brother Cao Zhi's talent and was afraid that he would compete with himself for the throne. He was once ordered to write a poem in a short time after seven steps. If he can't write it, he will be severely punished. This poem is a seven-step song written by Cao Zhi. This poem reflects the story of the mutually exclusive struggle within the feudal ruling group. The whole poem uses metaphor, beans and bean stalks are born from the same root, like brothers. The bean stalks burned under the pot are compared to the poet's brother Wei Wendi; The bean in the pot is a metaphor for the victim poet himself. The poet was very angry and asked, "We were born from the same root. Why are you persecuting me in such a hurry?"? In fact, the poet does not understand that in the feudal ruling group, in order to fight for power and profit, the struggle has always been a life-and-death struggle, which is very cruel. The poet wrote this poem in seven steps, which made Cao Pi lose the excuse of persecuting him. Although Cao Pi felt ashamed after seeing this poem, he was always afraid that the poet would compete with him for the throne and put him under house arrest for life.

Bunker is a military song in ancient Yuefu, written by Wang Changling, a famous frontier poet in Tang Dynasty. Most of his poems are based on the life of the frontier troops at that time. Through reviewing the history and remembering the famous Li Guang of Han Dynasty, this poem accuses the generals guarding the frontier of the poet's era of incompetence, hoping that a good general will emerge to drive out the enemy and keep the frontier. This poem is full of patriotic enthusiasm for national security.