They Made the Magic: Jim MacDonald

John James MacDonald (Jim or Jimmy) was born May 19, 1906 in Dundee, Scotland but grew up in Philadelphia.  In 1927 he moved to California and worked as an engineer.  His first career was in music as a drummer on the Dollar Steamship Lines.  This lead to an interest in percussion instruments and then in sound effects using musical and non-musical sounds together.  He received a call between cruises in 1934 to record music for a Mickey Mouse short at the Disney Studios and his career with Disney lasted over forty years and is mostly notably known as the voice of Mickey Mouse, beginning with Mickey and the Beanstalk.
He provided the yodeling for The Dwarfs Yodel Song, the whistling, and the sneezing.  MacDonald related in  Funnyworld number 18 to Michael Barrier:
In the early days, way back onto Snow White, they had the Fraunfelder family, a Swiss family, and they did a lot of the yodeling for the Dwarfs.  I played in the band; I played jugs and ocarina and different things.  We had a little five-or six-piece group, and I remember that Art Smith played the clarinet without and mouthpiece and all these oddball things, and we made the sound of that organ.  It was a very cute and funny sound for the organ, and when Walt hear it, he said, "That's great.  Now, this is a hpapy little group, they should be signing.  Maybe they could yodel." And he looked at me.  "Have you ever yodeled?" I said, "No, Walt."  He said, "Go on down to the stage and try it." - Walt's People Volume 7
He did the test yodel and the Fraufelders did the official cut, but when scenes changed, rather than bringing in the Fraufelders, MacDonald would fill in.  The same thing happened with Sneezy's sneezes.  Billy Gilbert did the Sneezes but when they needed to make a change, they called MacDonald.
MacDonald was the head sound effects man.  When asked what the most difficult sound he had to make was, he replied it was the sound of a spider web shimmering.  He also voiced chipmunk, Bruno and Gus/Jaq in Cinderella, Dormouse in Alice, Wolf in Sword and the Stone, Bees in Winnie the Pooh, and Humphrey the Bear.  You can 'see' MacDonald in Fantasia: his silhouette is visible playing the timpani.  Additionally, he was the drum player in The Firehouse Five Plus Two.
He retired in 1976 but returned to help with several projects including the rerecording of Fantasia and voicing the dragonfly in Rescuers.  MacDonald passed away in 1991 and named a Disney Legend in 1993.