The contrasting musical motifs of Blues music and Blanche’s Varsouviana polka symbolize the clash between the changing America of the mid-20th century and Blanche’s tendency to live in the past. Blues music—as is often the case in literature from this era—is an emblem of America’s increasingly diverse postwar society. Because of the era's many social and political changes, American popular culture started to be strongly influenced by people of color and immigrant communities. Blues music originated from the Black communities of the American South, and it's characterized by its soulful, heart-wrenching honesty and moving lyrics. It's also known for its use of improvisation, and its incorporation of the 12-bar chord progression.
The world that Blues celebrates and criticizes is the polar opposite of the sanitized, thoroughly white world of Southern gentility that Blanche inhabits. Polka music is cyclical and repetitive with an insistent downbeat, unlike the loose and improvisational structure of Blues songs. The Varsouviana's rhythms and its recurrence suggest Blanche’s inability to move beyond her grief, especially as the song is directly related to the night her husband committed suicide. When the audience hears polka music, it’s implied that it’s happening in Blanche’s imagination, as backdrop for memories of the traumatic past she's lost in. The Blues tells contemporary stories and engages with gritty reality, whereas the Varsouviana glosses over the details for the sake of aesthetics.
Everyone in the play can hear Blues music, however, and it's everywhere. Indeed, as Williams says in the introductory stage directions, in the French Quarter one is always "around the corner" from the sound of "a tinny piano being played with the infatuated fluency of brown fingers." Unlike Blanche’s polka, the Blues is not insular or situational. Whether it's in the background or playing loudly, it occurs frequently and becomes more prominent during intense moments in the play. The increasing volume of the Blues during critical scenes where Blanche’s secrets are exposed is a musical metaphor. It represents the encroachment of contemporary reality on Blanche's fantasy world. The auditory encroachment of the Blues into Blanche’s life is also a harbinger of her starting to mentally unravel. The more Blues she hears, the less rooted in reality she becomes.
The motif of artificial light appears throughout A Streetcar Named Desire, pointing to the ways people control one another and attempt to conceal things from one another. As in a lot of literature, light in this play represents truth, and shadows symbolize the things that people want to remain concealed. In this context, it’s important to note that most of the light that the audience sees in this play is artificial. Electric light or firelight, created and manipulated by humans, reflects the characters' attempts to control their realities and find things out about one another.
Blanche’s relationship with any sort of light is not a positive one. She avoids direct light as much as possible, especially sunlight, in an effort to hide her true age and troubled past. She also avoids bright light from bulbs, which she knows could also reveal her physical appearance in more detail than she wants. Blanche's preference for dim, artificial light allows her to maintain the illusion of youth and innocence; she doesn’t want to reveal anything outside of a timeline and a narrative she controls. She even goes as far as to cover the bulb in the lamp in Stella’s apartment with a paper shade, diffusing and softening the light.
Stanley Kowalski, on the other hand, seeks to expose the truth by literally forcing Blanche into the light whenever he can. Stanley likes to say things clearly and communicate bluntly, avoiding any nuance if possible. He’s annoyed by Blanche’s avoidance of light and eventually destroys her paper lamp-cover, symbolically removing her ability to soften and conceal her lies.
Stanley's manipulation of light also highlights the uneven power dynamics between Blanche and him. Blanche initially believes she holds the power in their dynamic, as she thinks she can manipulate Stanley with her sexuality. However, Stanley doesn’t find any of her efforts appealing in the way she intends. She’s in his apartment, and he’s the person paying for the electricity that powers the bulbs. When he reminds Stella of this, it always accompanies moments where he’s threatening to expose her or to ask too many questions. Stanley’s manipulation of artificial light is an expression of his desire to control Blanche, just as he controls Stella.
Stanley cleans himself a lot in A Streetcar Named Desire, but to a very different end than Blanche’s endless, morally purifying bathing. When he first meets Blanche, Stanley immediately removes his sweaty overshirt:
STANLEY: My clothes're stickin' to me. Do you mind if I make myself comfortable? [He starts to remove his shirt.]
Here, Stanley begins to "make himself comfortable" before Blanche has a chance to answer him. He doesn't actually care if she "minds" or not. Stanley wipes himself down, changes, and showers a lot, but he never takes baths. Blanche, by contrast, is always "soaking in a hot tub." She takes baths in order to try and wash the trauma and shame she's experienced out of her body. Stanley Kowalski, however, has no secrets that he feels he needs to cleanse himself of. Whenever he comes back into his apartment, he often beelines for the bathroom or removes his clothes. His cleansing rituals are brief and practical and have specific objectives. They’re meant to cleanse the surface of his body and to help him adjust to the heat. He’s not ashamed of the sweat, dirt, or grime from his daily life. He’s trying to “make himself comfortable.”
The closest Stanley comes to showering for symbolic reasons is when his friends dunk him in the shower in an attempt to sober him up after he beats Stella. He has nothing that he feels he needs to remove by extended soaking in scalding water. Stanley's emotionas are all on the surface, appearing and dissipating quickly. While Blanche's constant bathing represents a desperate attempt to wash away the stains of her history and her guilt, Stanley's quick cleanses show how easy it is for him to move on from the past. Stanley’s showers are intended to strip away temporary dirt from the surface, both physical and emotional.