The principals in the cast generally sang and spoke for themselves. A partial exception is Billie Burke's Glinda: Burke spoke her dialogue in her distinctive voice, but her singing was dubbed by Lorraine Bridges (who also contributed to the Lullabye League's performance in the Munchkinland sequence).
The Munchkins' voices, both in singing and spoken dialogue, were all dubbed by professional singers.
Vocal arranger Ken Darby worked closely with supervising sound recorder Douglas Shearer to create the distinctive sound of the Munchkins. His own choral group, the Ken Darby Singers, contributed to the Munchkins' sound. Members of the quartet the King's Men — John Dodson, Bud Linn, and Rad Robinson — provided the voices for the Lollipop Guild. (Darby was a former member of the quartet.) Pinto Colvig, who for many years was the voice of Disney's Goofy, also contributed to the Munchkins' sound. Darby provided the voice of the mayor of Munchkinland, portrayed onscreen by Charley Becker. Rad Robinson was the voice of the Munchkin coroner, portrayed onscreen by Meinhardt Raabe.
The Debutantes, a female vocal trio, provided voices for the Lullabye League and contributed to the song "Optimistic Voices."
The Rhythmettes also contributed to "Optimistic Voices."
- John Fricke, Jay Scarfone, William Stillman. The Wizard of Oz: The Official 50th Anniversary Pictorial History. Warner Books, 1989.
- Aljean Harmetz. The Making of the Wizard of Oz. New York, Knopf, 1977.