The theatres of Berlin and Frankfurt am Main were graced with drama by Ernst Toller, Bertolt Brecht, cabaret, and stage direction by Max Reinhardt and Erwin Piscator. Many theatre works were sympathetic towards Marxist themes, or were overt experiments in propaganda, such as the agitprop theatre by Brecht and Weill. Agitprop theatre is named through a combination of the words "agitation" and "propaganda". Its aim was to add elements of public protest (agitation) and persuasive politics (propaganda) to the theatre, in the hope of creating a more activist audience. Among other works, Brecht and Kurt Weill collaborated on the musical or opera "The Threepenny Opera" (1928), also filmed, which remains a popular evocation of the period.