Since its debut in 1942, Oklahoma!, the Rogers and Hammerstein classic, has been recognized as a milestone that revolutionized American musical theater. Its rousing title song also is the state song of Oklahoma. The term "musical comedy" generally is applied to theater works in which the play is interwoven with music, lyrics, and often dance. Some critics insist that musical comedy is America's distinctive and major contribution to world theater, although the genre is not exclusively an American invention.