What is the theme in The Threepenny Opera by Bertolt Brecht?

Another theme to consider is art and experience. The purpose of Brecht's plays (as they were originally staged by the author) was to create an experience that would force audiences out of their common perceptions of bourgeois theater (as merely a means of entertainment). His plays sought to instill a willingness to work for social change. Thus, ultimately, Brecht's plays were designed as tools of moral and social propaganda, yet they strangely lack what most propaganda, by definition, carries with it: a design for a Utopian social paradise that social reform might achieve.