(Welcome to The Disney Discourse, a recurring feature where Josh Spiegel discusses the latest in Disney news. He goes deep on everything from the animated classics to the theme parks to live-action franchises.)

Leave aside the actual designation: what defines “a Disney movie”? The Walt Disney Company has released plenty of films that don’t quite feel like something that may come from the House of Mouse, per se, so what is it that defines that subgenre of film? Your mileage may vary, but the ingredients that make up a Disney movie for me include the following: slapstick humor, memorable songs, a family-friendly and family-focused story (those aren’t always the same things), an embrace of just a wee bit of excess, a willingness to scare kids somewhat, a dollop of nostalgia, and more than a touch of technological ground-breaking.

Thus, with these notions in mind, it’s hard to imagine that, at least for the first 50 years of the studio’s feature-length filmography, there’s no more quintessential Disney movie than Mary Poppins.

A Ridiculous Story That Magically Works

This week, of course, heralds the arrival of a brand-new story featuring Mary Poppins from Walt Disney Pictures, nearly 55 years after the release of the original Mary Poppins in the summer of 1964. If anything about Mary Poppins Returns is striking (and not much is), it’s that watching other filmmakers try to echo the 1964 original only proves its uniquely unduplicable qualities. When you describe the events of Mary Poppins, directed by journeyman helmer Robert Stevenson, it’s easy to imagine that the film would have just been an utterly ridiculous failure.

Here goes: A sometimes-loving, sometimes-deadpan nanny (Julie Andrews) literally descends from the clouds to take care of two rambunctious children (Matthew Garber and Karen Dotrice), and make their parents (David Tomlinson and Glynis Johns) realize that they need to be more present and loving to their kids. The nanny achieves this goal by taking the kids on a series of misadventures, from traveling into a painting where they race alongside hand-drawn animated horses; to letting them laugh alongside a goofy old coot on the ceiling of his house; to taking the children to the rooftops of London to dance and sing alongside the most charming group of chimney-sweeps you’ll ever meet. The nanny also has the magical ability to make her umbrella talk, control the wind, and inspire giddiness in even the most stiffly proper British men. What happens in Mary Poppins is all quite silly, in its own way, but somehow, it all works.

While there’s not just one reason why Mary Poppins works so well, the chief reason it’s been able to stand the test of time for so long is its leading lady in her film debut. Julie Andrews wasn’t just playing a practically perfect character; everything about her performance suggested unqualified perfection. Where many of the actors in Mary Poppins are playing to the back row, Andrews rarely raises her voice, becoming a serenely calm figure whose seemingly all-knowing nature never feels overly coy or too mysterious. Though the character of Mary Poppins is herself not super-showy—either among the rest of the characters in the film, or just generally—it’s perfectly logical that Andrews received the Best Actress Oscar for her work. (As many cinephiles know, Andrews not only beat out Audrey Hepburn in My Fair Lady for the award. She’d been overlooked to play Eliza Doolittle, a role she originated on Broadway, by producer Jack Warner. Warner’s loss was Disney’s gain.)

The Instantly Iconic Music

Andrews aside, it’s impossible to think of Mary Poppins without thinking of its music. A “Disney movie” is one with music that you can’t stop humming, music that becomes instantly connected to the story in which it appears. What is The Lion King without “Circle of Life”? What is Pinocchio without “When You Wish Upon a Star”? And so on. But it’s hard to think of a lot of other Disney films with so many unbeatable, stone-cold classics as Mary Poppins.

From “A Spoonful of Sugar” to “Jolly Holiday” to “Chim Chim Cher-ee” to “Feed the Birds”, there’s arguably eight or nine songs, all written by the Sherman brothers, that serve as instantly memorable pieces of music. How many other films can boast that many songs that are earworms? One of the Oscars Mary Poppins won was, naturally, for Best Original Song, with “Chim Chim Cher-ee” as the victor, and only nominee, from the film. But the whole category could’ve just been songs from this film.

The expansive tone of the music suggested that Disney wasn’t just aiming to adapt the stories by P. L. Travers — the impresario had tried to get the rights from Travers for decades. He was trying to make an epic, sprawling musical in the vein of West Side Story or The Music Man. Several the songs are showstoppers, but the slower songs, including “Feed the Birds” (famously known as Disney’s favorite song in his later years), have more profundity and depth than you might associate with Disney.