The Beggar's Opera , London was seething with financial disparity . Charles Dickens highlighted London's underworld in 1838's Oliver Twist . Stephen Sondheim's 1979 musical, Sweeney Todd: The Demon Barber of Fleet Street , focuses on a crazed assassin determined to take his vengeance on the privileged class. In 1928, composer Kurt Weill teamed up with playwright Bertolt