What mood do the opening stage direction and setting description create? What effect is created with the music of the “blue piano”?

THere is a feeling of depression and incomprehension, "They told me to take a street-car named Desire." Blanche's first action in the play is one of confusion, ambivalence, disorientation. She cannot believe where she has ended up, standing at her sister's rundown New Orleans door step, or determine how she got there, on a pair of streetcars named Desire and Cemeteries. The blue piano is usually invoked in scenes of great passion; Williams states in the opening stage directions that it "expresses the spirit of the life" of Elysian Fields. It is indicated that this music should be most present in the parallel scenes of Stella's lustful reunion with Stanley in Scene 3 and Blanche's rape in Scene 9, as well as at the very beginning and end of the play, in the two moments that the Kowalskis share without Blanche in their lives.