Concurrent with "The Second Hurricane", Copland composed (for radio broadcast) "Prairie Journal" on a commission from the Columbia Broadcast System. This was one of his first pieces to convey the landscape of the American West. This emphasis on the frontier carried over to his ballet "Billy the Kid" (1938), which along with "El Salón México" became his first widespread public success. Copland's ballet music established him as an authentic composer of American music much as Stravinsky's ballet scores connected the composer with Russian music and came at an opportune time. He helped fill a vacuum for American choreographers to fill their dance repertory and tapped into an artistic groundswell, from the motion pictures of Busby Berkeley and Fred Astaire to the ballets of George Balanchine and Martha Graham, to both democratize and Americanize dance as an art form. In 1939, Copland completed his first two Hollywood film scores, for "Of Mice and Men" and "Our Town", and composed the radio score "John Henry", based on the folk ballad.