In J. D. Salinger’s The Catcher in the Rye, the passage discusses Holden’s walking to Broadway to purchase a record as a gift for his sister, Phoebe. The passage contributes to the development of themes in the novel because it shows how nostalgic he is. He says,
I started walking over toward Broadway, just for the hell of it, because I hadn't been over there in years.
In a sense, this nostalgia reflects his general sense of unhappiness with his life at this point in time and his yearning for what he views as a different, hopefully more idyllic time.
The passage also shows how much he loves his younger sister. He says of the record that he would like to buy for Phoebe, “it was one of the best records I ever heard,” and he goes on to describe it. It is about a small child who “wouldn't go out of the house because two of her front teeth were out and she was ashamed to.”
Holden loves small children, including Phoebe, because they have not yet lost their innocence. The image of the child conjures up thoughts of the vulnerability of a child not wanting to be hurt by the outside world and the indifference and injustice in the world at large.
Salinger also uses irony here, as he describes that
Estelle Fletcher... made [the record] about twenty years ago. She sings it very Dixieland and whorehouse...
Given this description, the record is perhaps is not the best gift for Phoebe or any small child who has not yet lost his or her innocence.
Overall, the passage develops the theme of Holden’s sense of isolation, his yearning for a time before loss of innocence, and, as a result, his love of and desire to protect small children like Phoebe.