Broadway songs were recorded around the turn of the century, but did not become widely popular outside their theatrical context until much later. Jerome Kern's "They Didn't Believe Me" was an early song that became popular nationwide. Kern's later innovations included a more believable plot than the rather shapeless stories built around songs of earlier works, beginning with "Show Boat" in 1927. George Gershwin was perhaps the most influential composer on Broadway, beginning with "Swanee" in 1919 and later works for jazz and orchestras. His most enduring composition may be the opera "Porgy and Bess", a story about two blacks, which Gershwin intended as a sort of "folk opera", a creation of a new style of American musical theater based on American idioms.