References to the polka music in streetcar named desire
The polka music plays at various points in A Streetcar Named Desire, when Blanche is feeling remorse for Allen’s death.
Scene one is where the polka music is first introduced Stanley asks Blanche about her marriage and the music triggers her thoughts from that night.
Blanches associates Polka with her young husband's suicide. Blanche and her husband were dancing the polka when she lashed out at him for his homosexual behavior, and he left the dance floor and shot himself. Music is played when she is reminded her past in general. Polka is only played in Blanche's mind.
In this scene it shows the music being played in Blanche's mind again. No one can hear it but her. After the shot is heard the music always stops to indicate that everything she once desired is gone and they're now separated.