The use of symbolism and motifs in A Streetcar Named Desire is illustrative of Williams's partiality toward Expressionism as his artistic outlet. The highly effective combinations of action/symbol and action/motif serve as the backbone of a play that combines fantasy and reality as they appear in the eyes of the main characters.
The combination of symbols and motifs helps the audience to connect with the emotions, or with the turmoils, of the character that represents the symbol. Altogether, symbolism is an essential part of characterization because it takes the audience to the deepest and most sacred world of the character. After all, a symbol is a unique representation of an special trait.
The most salient symbols in A Streetcar Named Desire are
a) The music as a trigger of memory, as the creator of atmosphere, and as a symbol of Blanche's emotional issues. We find from the beginning how the stage directions are adamant that there is a "blue piano" playing in the background, which symbolizes the culture of New Orleans. The Polka music playing during the introduction of Blanche and Stanley is representative of Stanley Kowalski's Polish heritage. Moreover, the use of the Varsouviana as the trigger of Blanche's trauma over her late husband's suicide is effective in mirroring Blanche's unstable moods.
b) The telephone, a modern contraption within the historical context of the play, was a completely unknown technology for Blanche. More than three times she tries to use the telephone to either contact an old acquaintance, to reach Western Union, or to talk to Mitch. None of her attempts work and she is always left waiting. Therefore, the telephone is a symbol of salvation not meant to save Blanche.
c) Poker, meat, alcohol- Poker and alcohol are Stanley's favorite diversions. It is the time for him to display his manliness as well as his dominance of his wife, and his home. His manliness is even more evidently marked in Scene One when he throws a slab of meat at Stella, which she catches with mischievous eyes. This is symbolic of the master/servant sex dominance that Stanley exerts over Stella, which she happily accepts to follow.
d) Lights and shadows- As part of the stage directions, Williams uses lights and shadows as a way to represent sanity versus insanity, reality versus fantasy, and good versus evil. The light is used against the shadowy wall,creating scenes, faces, or weird forms. The light is also dimmed, or made more bright, during sublime moments such as Blanche's memory of her husband's suicide. The light, or the lack thereof, is also symbolic of Blanche's lost youth, as she needs the light of shaded candles to admit herself to be seen by her much younger beau, Mitch.
Altogether, it is safe to assert the effectiveness of the use of symbolism in the play. It helps color the action with subtle things that suggest the depth of emotional investments made by the characters in pursue of what they want to make themselves happier.