Edgar Yipsel "Yip" Harburg was an American popular song lyricist and librettist who worked with many well-known composers. He wrote the lyrics to the standards "Brother, Can You Spare a Dime?", "April in Paris", and "It's Only a Paper Moon", as well as all of the songs for the film The Wizard of Oz, including "Over the Rainbow". Harburg was known for the social commentary of his lyrics, as well as his left-wing political leanings. He championed racial, sexual, and gender equality and labor unionism, and was an ardent critic of high society and religion.