Harold Arlen was an American composer of popular music, who composed over 500 songs, a number of which have become known worldwide. In addition to composing the songs for the 1939 film The Wizard of Oz, including "Over the Rainbow", which won him the Oscar for Best Original Song, he was nominated as composer for 8 other Oscar awards. Arlen is a highly regarded contributor to the Great American Songbook. "Over the Rainbow" was voted the 20th century's No. 1 song by the RIAA and the NEA.

The Wizard of Oz is a 1939 American musical fantasy film produced by Metro-Goldwyn-Mayer (MGM). An adaptation of L. Frank Baum's 1900 children's fantasy novel The Wonderful Wizard of Oz, it was primarily directed by Victor Fleming, who left production to take over the troubled Gone with the Wind. It stars Judy Garland, Frank Morgan, Ray Bolger, Bert Lahr, Jack Haley, Billie Burke and Margaret Hamilton. Noel Langley, Florence Ryerson and Edgar Allan Woolf received credit for the screenplay, while others made uncredited contributions. The music was composed by Harold Arlen and adapted by Herbert Stothart, with lyrics by Edgar "Yip" Harburg.