On the Great Movie Ride, before we reach the Wizard of Oz scene, we see a classic clip from The Sorcerer's Apprentice starring Mickey Mouse. It's short and only gets a quick mention on the ride but if you thought this scene seemed like a bit of an after-thought, well, there's a reason for it. The Sorcerer's Apprentice is there because another idea for that scene didn't make the final cut.
In order to understand why the Sorcerer's Apprentice is there now, we need to go back to the original plans for the Great Movie Ride. The original concept for The Great Movie Ride had quite a different fnale sequence than it does today. On today's ride, we pass by the characters from the Wizard of Oz that are almost at the Emerald City and we are lead into a large room with a movie screen in front, slightly above eye level. The tram enters the room and a montage of various films begins to play.
The original idea for the ride was quite different. The original idea for the scene was to have the area that is now occupied by the Sorcerer's Apprentice to be a tornado scene, where guests would feel as if they were in the tornado that brought Dorothy from Kansas to Oz. This would to be a perfect segue into the Munchkin village scene and carry on to additional Wizard of Oz scenes.
So what happened? Well, first, the legal dispute between Disney and MGM started, which limited Disney's ability to depict more scenes from the Wizard of Oz. Given the tight budget Disney was on, Disney couldn't afford to pay MGM more money for the rights and Disney had to cut down the amount of time the Wizard of Oz portion of the ride took up. Ultimately, Imagineers decided to cut out the tornado scene, as well as a much different grand finale.
But there was a problem. The room that was meant to house the tornado scene had already been built! The Imagineers decided rather than scrapping it entirely, they pulled from their existing film catalog and transformed the wind-blowing effect area into one that used Disney's animated classic, Fantasia. Instead of a flying house and a wicked witch flying by, Mickey Mouse in full "Sorcerer's Apprentice" costume, was shown commanding the enchanted waters. The reason why the fans are still blowing on you is because instead of a tornado, the Fantasia sequence takes place in the middle of a swirl of wind as Sorcerer Mickey raises the waters for the enchanted brooms to continue working. This is also why why the area surrounding the film is decorated the way it is.