Then the carousel started, and I watched her go around. There were only five or six other kids on the ride, and the song the carousel was playing was 'Smoke Gets in Your Eyes.'
In the penultimate chapter of Salinger's The Catcher in the Rye (1951), the protagonist and narrator, Holden Caulfield, is at the park with his younger sister, Phoebe. The novel is a coming-of-age story and is very much about Holden losing his innocence, even though he is already a jaded and cynical teenager.
Phoebe, as children often do in stories, stands for innocence, optimism, and purity, all qualities that Holden has lost over the course of the novel. The carousel, too, can be seen to symbolize these qualities and stand in stark contrast to Holden's personality and experiences.
This scene takes place very nearly at the end of the novel, and throughout the book, Holden struggles to connect with people (such as friends, teachers, schoolmates, and girls). Phoebe is really the only one he feels comfortable around and the only one he can talk to. He loves her because she is his sister, of course, but I think he also loves her because she has yet to be tainted by the world like he has. He watches her ride the carousel and is overwhelmed with emotion: "I felt so damn happy all of a sudden, the way old Phoebe kept going around and around. I was damn near bawling" (213).
What makes this scene even more poignant is that we know that he has some sort of breakdown and is telling the story from an institution. So Phoebe and the carousel represent what is good in the world: a sharp contrast to his mental state and jaundiced view of most everything around him.