Ed Love
Just thought I should mention one of the lesser known animators who worked on the movie:
"At the time, The Sorcerer's Apprentice was in production, Walt Disney wanted to hire his greatest animators with talent to work on the film - and at the time, the Nine Old Men were only new at the time when they got to the Disney Studios, and Les Clark was the only one of the members who was experienced, and that was working on Sorcerer's Apprentice. However, the Mickey animators have a lot of Riley Thompson, with a bit of Les Clark, and also includes quite a lot of unknown animators such as Marvin Woodward and Ed Love. However, Preston Blair is pretty much well known in the animation industry as he did a lot of cartoons for the MGM Animation Studios (and not Tom and Jerry). Although another uncredited animator that animated on numerous shorts for Disney at that period was Bob Wickersham. He animated a lot of Mickey in Thru the Mirror, and a bit of animation of Mickey here of Mickey trying to pour the water away. Bob was really known as "Bob Wick" in his comic work.
It appears to be that one of the Mickey animators is also effects animator and one of my favourites Cy Young. He really does the scenes of Mickey holding onto the book, and some of the brooms marching into the water. Although, he is uncredited, but I think we have seen enough of Young in 'Fantasia' already, haven't we?
Ed Love's animation of the brooms multiplying is amusing - I'm not saying that the drawings and the animation is funny - but I'm meaning funny in terms of visual storytelling. For instance, Mickey has chopped the broomstick into tiny pieces with an Axe, and those tiny pieces suddenly start forming and multiplying into dozens and dozens of broomsticks, with means ten times more trouble for Mickey. Those scenes were later parodied in The Simpsons.
Love is another Disney animator who has been in the backgrounds of Disney animation for a long time, he began his Disney career very early in the 1930's, and left during the infamous Disney strike to work for MGM and other companies."
There is an article about him here: http://www.independent.co.uk/news/people/obituary-ed-love-1348345.html