Why should we also write poems when we already have a small preface in the pipa line?

The preface and poems in "Pipa Xing" complement and expand each other.

The preface mainly explains the time, place, characters and background of the story, as well as the scene and purpose of pipa playing. Although the preface is short, it provides the basic framework and background of the poem, and provides the necessary clues for readers to understand the content of the poem.

The poems are more in-depth description and lyrical based on the preface. By describing the details of pipa playing and the beauty of music, the poem expresses the poet's love for the art of pipa and his sympathy and respect for pipa players.

In addition, the poem also organically combines the artistic expression of music with the poet's emotional feelings through the use of rich images and vivid descriptions, further expanding the plot and characters provided by the Xiaoxu image.

Therefore, the preface and the poem complement each other and together constitute a complete and vivid narrative poem.