In describing Tennessee Williams's artistic presentation of his play, A Streetcar Named Desire, Arthur Miller wrote that music served to underline motifs:
[Williams's] rhapsodic insistence that form serve his utterance rather than dominating and cramping it...
To maintain the continuity of his play, Williams has not employed separate acts; instead he has scenes that are thematic using symbols and music to highlight these motifs. For instance, Williams uses the blues to connote animalistic pleasure--such as in Scene Four when Stanley wins Stella back and smiles over her head to Blanche--or in moments of leisure as the men play cards or when people relax and drink. Blues are also used in highly charged emotional scenes involving sexual desires, or when Stanley consoles Stella after she comes down the stairs. It plays during the rape scene. The polka which is heard only by Blanche signals crucial moments in the play. And, once the audience learns that this music is what played in the ballroom where Blanche renounced her young husband, they are alerted to disaster when this music plays.
The symbolic streetcar is also employed as a literary element. Blanche must ride this streetcar to arrive at Stella's and she alludes to it in her remark, "Haven't you ever ridden that streetcar named Desire?" The streetcar continues running, just as Blanche and the others must see their lives through to the end. For, Blanche must transfer from Desire to a streetcar named Cemeteries and then come to Elysian Fields.
These motifs underscored by music and symbol develop the theme of Class Conflict as Blanche of the aristocratic South comes into conflict with Stanley Kowalski of the North who is a factory worker. Her sister's and her Belle Reve, the plantation, have been replaced by a second story flat in the Vieux Carre of New Orleans and Blanche, as respresentative of this dreamy and romantic era, is in conflict with the animalistic Stanley who has his "party of apes" and has taken her sister Stella "down off them columns" and she has "loved it."
Another theme is that of Gender Roles. Mitch has elevated Blanche to the Southern lady, and when he finds out that she does not fulfill this role, he rejects her, causing her the loss of her final opportunity. Blanche understands the subservient role of women as she repeats, "I have always been dependent upon the kindness of strangers," but her sexual desires cause her to say and act outside what is expected of her, a behavior that effects this conflict.
A third major theme is that of Violence and Cruelty. When Blanche objects to Stanley's violent nature, Stella tries to explain to her that "there are things that happen between a man and woman in the dark" that mitigate the violence. This Blanche does not understand even though the upstairs residents have the same violence in their relationship. As the streetcar passes down the street, Blanche tells Stella she is just talking about hard, cruel desire, "the name of that rattle-trap streetcar." It is a place where Blanche has been, and the streetcar Desire has brought her to Stella's apartment. And, it is Stanley's violent rape and cruelty--he tells her, "We've had this date with each other from the beginning"--which drive poor Blanche to her maddess, an act that demonstrates the continuity of violence that is hard to break.