In a novel written in verse, poetry serves as a way to tell the story and convey emotion in a unique and rhythmic way. The specific form and style of the poetry can help to set the tone and atmosphere of the story, and can also provide insight into the characters and their experiences. For example, the use of rhyme and meter can create a sense of musicality and movement, while free verse or more experimental forms can convey a sense of chaos or unpredictability.
Using different kinds of poetry can also help to highlight different aspects of the story and give the reader a deeper understanding of the characters and their motivations. For example, the use of sonnets might convey a sense of traditional, formal love, while the use of haikus could convey a sense of simplicity and contemplation.
Overall, the use of poetry in a novel can add depth and complexity to the story and enhance the reader's experience by creating a sense of rhythm and musicality, and by allowing the author to convey emotion and meaning in a unique and evocative way.