Interesting fact:

For its general release, Fantasia was cut to reduce its running time, but at two hours and six minutes, the film is still the longest animated feature the studio has ever made. The scope and soundstage of Fantasia were too grand for the standard theater of the 1940s, but instead of making a film that worked within the limitations of technology, Disney and his team had to develop a way to upgrade theaters to match the concert experience of the film.