As most of you know, Whistle While You Work, appears in the film Snow White and the Seven Dwarfs while Snow White and her animal friends work to tidy up the cottage. In her line of thinking, it's awfully untidy, and maybe they will let her stay if she cleans! (any house guest who offers to clean, can stay in my book, we won't address the whole entering without permission issue). Anyway, the song was written by Frank Churchill and Larry Morey.
It is surprising all the different places you can hear the song, check them out:
1938: You can hear the song in the Oscar-winning film You Can't Take it With You
1940: In Billposters, Donald Duck and Goofy were heard whistling and humming the song
1941: Warner-Brothers film noir Crime Drama Out of the Fog
1958: Looney Tunes cartoon "Weasel While You Work"
1987: The first episode of DuckTales, Scrooge makes a reference by telling one of his employees, "There'll be no whistling while you work!"
1988: In Splash Too, during a scene when Allen and Madison fix up their new home and afterwards Madison whistles the song as well while making Breakfast.
1990: It is also the first song featured in the Disney Sing-Along Songs video Disneyland Fun.
1990: In Kidsongs, a day at Camp, the kids sing the song while working on projects.