Answer: Blanche reveals to Mitch that she married a man who turned out to be gay, and after she found that out, she called him “disgusting,” and he killed himself.
Explanation:
As Blanche narrates this account, the Varsouviana polka plays in the background, because it´s the music that was playing during the event she remembers. This auditory hallucination embodies her guilt and delusion, as well as her failure to escape her past. The music stopping with the gunshot represents how the music in her life stopped that night.