From the Disney Parks Blog:

"We’ve all heard it and we’ve all sung it and that’s what makes “it’s a small world” one of the most translated and performed songs on earth. Richard and Robert Sherman are the talented brothers who wrote the famous tune that you can’t get out of your head. You’ve probably also heard their other wonderful pieces of work throughout Disneyland park – past and present: Enchanted Tiki Room, Carousel of Progress, Adventures Through Space, as well as a long list of Disney motion-picture musical scores that includes “Mary Poppins,” “The Jungle Book,” “Bedknobs and Broomsticks,” “The Aristocats” and “Winnie the Pooh.” Next week the Sherman Brothers will be given one of the most prestigious honors that a Disney cast member can receive, a window on Main Street U.S.A. at Disneyland park.

Direct link to the Parks blog with video of Walt & the Shermand Brothers singing together.