 He collaborated as lyricist or librettist with Oscar Hammerstein II, Jerome Kern, Louis Hirsch, Herbert Stothart, Vincent Youmans, George Gershwin, and Sigmund Romberg.He was a charter member of ASCAP in 1914, serving as its director (1920–1963), vice president (1936–1940), and finally president (1950–1953).Harbach was also an inductee of the Songwriter's Hall of Fame.