There is, indeed, a somewhat satiric tone to Fitzgerald's tableau of the Jazz Age with its amorality, materialism, and shallowness. In fact, his novel is a satire of the "American Dream" that finds its value in the acquistition of money and social position. In seeking tone regarding the description of the theme in these decadent social and moral values of Gatsby's guests and the other characters of the novel, you will notice a cynicism in Nick Carraway's voice as narrator as he describes Gatsby's guests and the others involved in the empty pursuit of pleasure.
In order to find examples of Nick's cynicism and an overall satirical tone of the novel, you may wish to conduct a perusal of Chapter Two which describes the Valley of Ashes and the party in New York, in which the pretentious and vulgar speech and behavior of those in the apartment repulse Nick. More examples will be found with a look at Chapter Three and the ostentatious guests, the jaded guests, and those who are merely shallow reflections of other people, as well as an examination of Chapter Four in which Daisy sheds tears of joy at the resplendence of Gatsby's home and buries her head in his many-colored shirts and Gatsby glows in her attention to his luxuries.
That Nick is cynical about the American Dream as well as being repulsed by the socially and decadent elite and their wealth-obsessed culture is evidenced in the final chapters as he tells Gatsby that he is worth "the whole d--bunch!" Certainly, too, the final chapter expresses Nick's disillusionment in the Jazz Age.
In his closing remarks, some critics feel that Nick moves from cynical disillusionment to a tone of melancholy,
Gatsby believed in the green light, the orgastic future that year by year recedes before us. It eluded us then, but that’s no matter—tomorrow we will run faster, stretch out our arms farther. . . . And then one fine morning—
So we beat on, boats against the current, borne back ceaselessly into the past.
Thus, these critics feel that Nick is less cynical than he is disappointed in the ideal. Therefore, the tone of the novel for these critics is melancholic.
Hope this helped you!
thank you very much. this is a great jumping off point. im gonna try to dig for some more examples. I really do appreciate the help.