There cannot be one verdict on "Fantasia". There must be eight: one for each of the seven segments, and an eighth for the film as a whole - for, varied though the seven segments are, they undeniably belong together. And, alas, space does not permit me to lay out all eight verdicts. I shall have to confine myself to details representative of the whole. At any rate, I shall try.
We learn the modus operandi of "Fantasia", the linking theme, in the second segment - an abridged version of Tchaikovsky's "Nutcracker" suite. (Missing are the overture and the march.) Tchaikovsky's ballet involves anthropomorphising inanimate things, plus the odd tiny animal. So does Disney's "Nutcracker". But Disney has thrown out the particular details. The Chinese Dance is danced by mushrooms (who look, but are not, Chinese); the Arabian Dance by "Arabian" goldfish; the Russian dance by "Russian" thistles and orchids. Sometimes it goes further: "Waltz of the Flowers" shows two entire changes of seasons, with leaves, fairies, seed pods, seeds, snowflakes - everything but flowers. But in ignoring the letter of the instructions Disney is perfectly true to the spirit. Indeed he is more true to the spirit than the original ballet - for, let's face it: stage ballet is a degenerate and over-formalised art, which makes some of the world's most exciting music dull as wallpaper. Disney's amazing images express Tchaikovsky's sense of motion more than earthbound dancers ever could. This, one feels, is the kind of thing ballet music was TRULY designed for. The same goes to a lesser extent for the other two pieces of ballet music on the program.
This basic device - ignoring explicit instructions, but remaining true to the spirit - is carried through into every segment. (Some segments are better than others, but none can be called a failure.) Dukas's "The Sorcerer's Apprentice" has been turned into a Mickey Mouse cartoon - but it's the best Mickey Mouse cartoon ever made; and we realise that the story of the Sorcerer's Apprentice is really the archetype that all of the best Mickey Mouse cartoons had been reaching towards, all along. The Pastoral Symphony adheres to Beethoven's program but moves everything from the woods of Central Europe to a dreamland from classical mythology. (The second movement - the section with the courting centaurs - is a failure. For once the spirit as well as the letter of Beethoven is ignored. Unfortunately some critics cannot see beyond this movement to the superb interpretations that flank it on either side.)
I doubt that so much genuine creative work has gone into a film, before or since - even if you don't count the contributions made by the composers. What's my favourite film? I really don't know. But if you tell me that I must sit in a large dark cinema for two hours; and ask me what I would like to occupy my eyes and ears over those two hours, I would answer, without hesitation, Fantasia.