“The Nightingale and the Rose” is written as a fairy tale. Its short length, plot-driven narrative, and overall whimsical tone are typical of the genre. What's more, its events take place in a world with no definite time or place, and the story involves elements of the supernatural.
However, while conforming to the stylistic tropes of fairy tales, Wilde subverts the genre with his refusal to end the story with the typical happy ending. Whereas traditional fairy tales feature archetypal heroes and villains who are either rewarded for their virtue or punished for their wickedness, “The Nightingale and the Rose” is more ambiguous. While the Nightingale is presented as a virtuous heroine, her heroic sacrifice proves to be in vain. Meanwhile, the Student, who is presented as shallow and pretentious, comes out of the tale largely unscathed. In this story, then, goodness goes unrewarded and vices go unpunished. This reversal of fortunes and lack of a neat ending makes for an ambiguous tale that reflects Wilde’s aversion to moralistic writing. As he wrote in the preface to his most famous book, The Picture of Dorian Gray, Wilde believed that “there is no such thing as a moral or immoral book”.
Published in 1888 as part of Wilde’s collection “The Happy Prince and Other Tales,” “The Nightingale and the Rose” falls under the genre of Victorian children’s literature. Children’s literature became extremely popular in the Victorian period, with stories usually including moral instruction but also elements of fantasy and adventure.
Similar to the fairy tale genre, though, Wilde subverts the expectations of Victorian children’s literature while maintaining the sense of wonder that's typical of the genre. Indeed, Wilde wrote that his stories were meant “partly for children, and partly for those who kept childlike faculties of wonder and joy.” The fantastical and whimsical elements of the story—such as animals that can speak and feel—relies on a reader (whether child or adult) who's willing to suspend reality. In this way, Wilde uses a form of literature that champions imagination over realism. To that end, the story itself mocks the Student's rationalist values. When the Nightingale tells the Student she will find him a rose, for instance, the Student cannot understand her:
The Student looked up from the grass, and listened, but he could not understand what the Nightingale was saying to him, for he only knew the things that are written down in books.
The Student’s inability to understand the Nightingale (unlike the reader) suggests that he's unable to grasp things that lie beyond the narrow scope of his bookish knowledge. In turn, the story draws on fantastical elements as a way of suggesting that there's more to know in the world than what's written in books.