Broadway.

The movies and radio killed vaudeville, but Broadway provided a string of brilliant musical productions , many by younger composers and lyricists. The revue format consisting of a series of unconnected acts remained popular; in addition to the annual Ziegfeld Follies that had started before the war, there were the George White Scandals, Irving Berlin's Music Box Revues, Earl Carroll's Vanities, and others. The hit shows included No, No, Nanette (Vincent Youmans and Otto Harbach), Show Boat (Jerome Kern and Oscar Hammerstein II), A Connecticut Yankee (Richard Rodgers and Lorenz Hart), and Lady, Be Good! (George and Ira Gershwin).

Source:

Ethan Madden, Better Foot Forward: The History of American Musical Theater (New York: Grossman, 1976).