Music plays an important role in A Streetcar named Desire because it appears in almost every scene and expresses the atmosphere in a very distinct way. It is permeated by the different type of music: the blue piano and the Varsouviana Polka. Each one appears in scenes which are occupied by a certain emotional state of Blanche. Therefore, music helps us to understand the mental condition of Blanche and the mood of this play, which cannot be depicted by lines and actions.