What is the importance of music in Appointment in Samarra?

Appointment in Samarra is set right between the end of the Jazz Age and the beginning of the Depression. As the Roaring Twenties came to an end, the country sank into the despair brought about by economic decline. With an orchestra often playing in the background and a crowd tearing up the dance floor, John O’Hara uses music to immerse readers in the spirit of those times and to create atmospheres in which the characters’ moods come to life. In chapter 4, Julian and Caroline are at the Country Club talking about the effects that the incident with Harry is having on Julian’s image and negotiating whether Caroline will agree to keep her promise to go out to the car with Julian. The band is playing music, and Julian cannot help but get distracted because his “ear for jazz was superb.” When he tells Caroline what he is really thinking about—that the band is lousy and that it is a “foolish economy” to save money on an orchestra—she gets upset because she senses that Julian is not taking their conversation seriously. The exchange gives the reader a subtle yet important insight into Julian’s failure to meet his wife’s expectations. It also depicts his inability to fit into his superficial environment: could Julian’s comments about the band be perhaps more consequential than the petty worries triggered by his impulsive behavior? The scene is also indicative of the times because it emphasizes the fact that thriftiness is prioritized over artistic quality. Arrogant and obnoxious as he may be, Julian appears as a truth-teller whose sensibility for music is worthy of praise. The narrator’s sympathies are clearly with him: “After all,” Julian says, “the most important thing at a dance is the music, isn’t it?”
When Julian finally goes, he does so with music. He says his final farewell to life while pounding his feet to the tunes of Jean Godkette and Paul Whiteman. The random selection of records he makes after laying them out on the floor and spinning a spoon to select them adds an element of fortitude to his final moments, as if chance could still change the course of the story. A final mishap highlights the misfortunes of his short and damaged life as Julian prepares to say goodbye:  

He played only three records in this way, because he was pounding his feet, keeping time, and he broke one of his most favorite, Whiteman’s Lady of the Evening, valuable because it has the fanciest trick ending ever put on a record. He wanted to cry but he could not. He wanted to pick up the pieces. He reached over to pick them up, and lost his balance and sat down on another record, crushing it unmusically.