Animation historian John Canemaker calls it "one of the most exquisite examples of Disney fantasy ever created." It's not a princess movie — it's the Nutcracker sequence in the 1940 classic Fantasia.

As we celebrate the 75th anniversary of a film that has introduced generations of children — and, perhaps just as often, adults — to classical music, I'm telling the stories behind each of the sequences in Fantasia. Previously, I wrote about the opening Toccata and Fugue; today, I'm looking at the second sequence in the picture, set to the music of Tchaikovsky's Nutcracker Suite.

Not the whole suite, though: Disney skips the overture and march, cutting straight to the Dance of the Sugar-Plum Fairy as sprite-like pixies awaken to begin a ballet of the seasons. The entire sequence is a tour de force of animation, putting Disney's crack team to one of their utmost tests in a series of scenes that cast a magical glow over painstakingly drawn woodland scenes.

Disney had long taken the convincing portrayal of nature as the acid test of the sophisticated animation techniques his studio was developing. The great outdoors had been explored in some of the studio's most ambitious shorts, and were the artfully rendered setting of Bambi, the 1942 feature that represented the culmination of Disney's naturalistic style.

In keeping with the approach used throughout Fantasia, Disney deployed his most skilled animators to work on the scenes that would best display their respective strengths. Character animator Art Babbitt, for example — whose work on The Three Little Pigs had been a breakthrough in expressive animation — took the lead on the charming mushrooms that perform the Chinese Dance.

The Chinese Dance is regarded by animation historians as a textbook example of successful character animation. The smallest mushroom, writes John Culhane in his definitive book on Fantasia, "projects his personality as vividly as any character in the Disney galaxy — yet he has no dialogue, makes no sound, and doesn't even have a face or hands to gesture with." The scene, continues Culhane, "is the best example of the Disney Studio's genius for compression, its ability to spring an entire character from a simple design in motion."

It's also an example of the animators' careful attention to the music of Fantasia. That cute little mushroom represents the trill of Tchaikovsky's flute, while the larger mushrooms plod about to the pizzicato plucking of the string section. "I don't know a hell of a lot about music," admitted Babbitt, but he listened closely enough that his animation merges organically with the music — despite the fact that the music was originally written for a fantasy ballet, not for mushrooms wiggling like the Three Stooges. ("We sold a million little salt and pepper shakers" in the shape of those mushrooms, remembered Walt Disney's nephew Roy.)

The extended underwater scene showcased the abilities of a team that had multiple animators whose full-time job on some Disney features was exclusively to draw bubbles. The challenge for the animators was to both convincingly portray an undersea world (appropriate for Fantasia, given that Walt Disney once described classical music as "an emotional bath") and to suggest the movements of the dancers for whom the music had been written. An actual Middle Eastern dancer — one Princess Omar — even visited the studios to model for the movements of the diaphanous fish whose swimming was described unsubtly by Walt Disney himself as "almost like a hootchie-cooch."

In other scenes, the animators were careful not to anthropomorphize their subjects. For the dancing leaves that signal the transition to autumn, for example, Disney wanted to create a three-dimensional airborne dance that was all the more enchanting for its authenticity. If you draw a leaf to resemble a human dancer, he pointed out, "you're limiting it to what a human can do."

Creating the breathtakingly intricate dance of the frost sprites on the freezing water required some of the most elaborate animation effects ever attempted in the pre-digital era. For some cels, several painting and drawing techniques were used on every single frame, requiring up to 24 hours of work for just one second of screen time. For the climactic dance of spiraling snowflakes, paintings of the flakes were mounted on mechanical gears that were spun in front of the camera; the rest of the animation was added to each frame by means of double exposure.

Fantasia Disney

The result was more than worth the effort. Perhaps the single finest sequence in Fantasia, and an enduring masterpiece of the art of animation, the Nutcracker scene also helped to create a newfound appreciation for Tchaikovsky's music.

In fact, Fantasia may have done more for The Nutcracker as a piece of music than for any other piece featured in the film. In 1940, Tchaikovsky's 1892 ballet was relatively obscure: the ballet had never been performed in its entirety in the United States, and was barely seen outside of Russia at all. Four years after Fantasia was released, the San Francisco Ballet staged the U.S. premiere of the complete ballet, and by the time George Balanchine's New York City Ballet Nutcracker premiered in 1954, the work was on a fast track to become a permanent Christmas staple in cities across the country.

Disney's ambition with the Nutcracker sequence in Fantasia was to transcend the real. "When it's common in your imagination but hasn't been seen on the screen," said Disney, "then it's effective. You haven't seen anything like that in action, you haven't seen anything like that on the stage. It's impossible."