"Ode to Four Poems" refers not to four different poems, but to four parts in the Book of Songs. The Book of Songs is the earliest collection of poems in China, which is divided into three parts according to the different contents and forms: style, elegance and ode. Among them, "Wind" is a local folk song; "elegance" is the formal elegance of the court, including "elegance" and "elegance"; "Ode" is a eulogy used in sacrifice. Ode to Ya is called three poems, but in fact "Ya" is divided into "Ya" and "Ya", so it is collectively called "Four Poems".