The Book of Songs is a four-character poem.

Four-character poem prevailed in the Western Zhou Dynasty, and it is one of the oldest genre forms of ancient Chinese poetry. During the Spring and Autumn Period, the Warring States Period, Qin and Han Dynasties, four-character poems were the mainstay of the ruling and opposition parties and the people. The most famous representative collection of four-character poems is The Book of Songs, which is the earliest collection of poems in China.