Marcus Samuel Blitzstein, 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 by Paul Dessau. Blitzstein also composed music for films, such as Surf and Seaweed (1931) and The Spanish Earth (1937), and he contributed two songs to the original 1960 production of Hellman's play Toys in the Attic.

The Cradle Will Rock is a 1937 play in music by Marc Blitzstein. Originally a part of the Federal Theatre Project, it was directed by Orson Welles and produced by John Houseman. Set in Steeltown, U.S.A., the Brechtian allegory of corruption and corporate greed includes a panoply of social figures. It follows the efforts of Larry Foreman to unionize the town's workers and combat the powerful industrialist Mr. Mister, who controls the town's factory, press, church, and social organization. The piece is almost entirely sung-through, giving it many operatic qualities, although Blitzstein included popular song styles of the time.