While naturally agreeing with most all the classic-era choices above, I'm surprised no one has yet mentioned Cliff Edwards (aka "Jiminy Cricket")...although of course, Julie Andrews comes first and foremost to mind. Norma Zimmer (yes, from the Lawrence Welk show) can be thanked for some lovely, and frequently uncredited work: solos in the titles of "Song of the South" and "Cinderella," lead "floral vocals" in the Original Tiki Room, and too many film and theme park background vocals to mention. Since Annette was referenced above, remember too the Mouseketeers who were the show's principle singers--Tommy Cole and Darlene Gillespie. Lastly--how about the great Betty Taylor, "Slue Foot Sue" of the Disneyland Golden Horseshoe, and on records and the occasional attraction as well?