Marcus Samuel "Marc" Blitzstein (March 2, 1905 – January 22, 1964), was an American composer, lyricist, and librettist. He won national attention in 1937 when his pro-union musical The Cradle Will Rock, directed by Orson Welles, was shut down by the Works Progress Administration. He is known for The Cradle Will Rock and for his Off-Broadway translation/adaptation of The Threepenny Opera by Bertolt Brecht and Kurt Weill. His works also include the opera Regina, an adaptation of Lillian Hellman's play The Little Foxes; the Broadway musical Juno, based on Seán O'Casey's play Juno and the Paycock; and No for an Answer. He completed translation/adaptations of Brecht's and Weill's musical play Rise and Fall of the City of Mahagonny and of Brecht's play Mother Courage and Her Children with music