Walt Disney's favorite song was from the movie Mary Poppins, but it wasn't Supercalifragilisticexpialidocious. (the one most people normally guess.)
His favorite song was Feed the Birds (Tuppence a Bag). Walt would often ask the brothers to "Play it" after meeting with them on other issues, most often on Friday afternoons and they always knew which song he meant and always obliged. On the occasion of what would have been Walt Disney's 100th birthday, Richard Sherman performed the song one more time.... for Walt, at DISNEYLAND.