Disney’s newest feature, Frozen, is many things: a loose adaptation of Hans Christian Anderson’s The Snow Queen, a moving tale of sisterly love, an action-packed comedy that shares more than a bit of DNA with Disney’s own Tangled. (One example: In that film, the male hero’s best buddy is a dog-like horse named Maximus. In this film, the male hero’s best buddy is a dog-like reindeer named Sven.)

Frozen also happens to be an old-fashioned animated musical, featuring eight catchy songs by the husband-and-wife team of Robert Lopez and Kristen Anderson-Lopez. The pair has worked with Disney once before, writing tunes for 2011’s Winnie the Pooh — though Lopez is best known as the Tony-winning co-writer of edgy Broadway hits Avenue Q and The Book of Mormon. (Talk about range!)

But despite the couple’s pedigree — and the theater bona fides of the film’s cast, including Tony winner Idina Menzel and Broadway alumni Kristen Bell, Jonathan Groff, and Josh Gad — Frozen‘s massive advertising campaign has largely neglected to mention the movie’s full slate of original tunes. Which is totally understandable, at least according to the composers themselves. “I think that the movie is so much more than a musical,” Lopez tells EW. “It’s not what you might think of when you hear the word ‘musical.’ You might think of something with kicklines and stuff like that — but it’s really not that. So I understand why they’d do that” — i.e. downplay his and his wife’s work. For the record, the company did the same thing with Tangled, another stealth musical that boasted songs by lyricist Glenn Slater and Academy Award-winning Disney mainstay Alan Menken.

So fine; maybe this newest project shouldn’t be reduced to the sum of its songs. But prospective viewers deserve to know one thing before they step into a theater that’s showing Frozen: Regardless of how they feel about musicals as a genre, they will walk out humming Lopez and Anderson-Lopez’s work.

Blame a diverse network of influences — including classic Disney Renaissance films like The Little Mermaid and Beauty and the Beast, Latin-inflected cabaret, old-timey soft shoe numbers, and contemporary pop divas like Lady Gaga and Adele — for the music’s stickiness. That last group proved particularly important for the film’s big showpiece number “Let It Go,” a celebration of empowerment that sounds like a more radio-friendly take on Wicked‘s “Defying Gravity.” (There’s a reason for that: The Lopezes designed the tune specifically for Menzel, Broadway’s original Elphaba.)

As Anderson-Lopez recalls, “Let It Go” was the first song she and her husband wrote that ended up staying in the movie. Its composition also led the film’s team to rethink its entire approach to the character of Elsa, a.k.a. Frozen‘s take on Hans Christian Anderson’s Snow Queen. In previous drafts, Menzel’s character had a villainous bent. Once the couple penned “Let It Go,” though, they finally began to understand what really made Elsa tick: She’s a scared, repressed teenager, not a malicious ice queen. “As the movie got rewritten and rewritten around ‘Let It Go’ to earn that moment,” Lopez explains, “she became more and more the protagonist along with Anna” — Elsa’s younger sister, voiced by Bell.

Clearly, then, Frozen‘s songs aren’t incidental — they’re integral both to its plot and its character development. And the Lopezes didn’t write them in a vacuum: “We worked with the team [screenwriter Jennifer Lee and co-directors Lee and Chris Buck] every day, really,” Lopez says. “We figured out not just the placements of the songs within the story but also what the story would be.” The only thing aspect of Frozen‘s plot that stayed constant throughout the development process was its feel-good ending; everything else went through constant revisions, hashed and rehashed by both its directors and composers. You can get a sense of those revisions by taking a listen to Frozen‘s deluxe soundtrack (out now), which comes complete with a second disk stuffed with songs ultimately excised from the movie. Among them: Another Elsa/Anna duet set in Elsa’s snow palace, and an exposition-heavy number about a trollish prophecy that was evidently once important to the film’s plot.

One thing that did make it into Frozen‘s final draft: A lyric that may sound strikingly familiar to fans of a certain cult sitcom. Anna’s big, romantic duet with her love interest Prince Hans finds the two marveling about how much they have in common, even though they’ve just met. One exchange goes like this:

Hans: We finish each other’s–

Anna: Sandwiches!

Hans: That’s what I was gonna say!

“It was an unconscious callback to Arrested Development,” Lopez says with a laugh when asked if he meant to recall Michael and Lindsay Bluth. “I think we had seen [that] episode once, and we did the joke, and realized that we had kind of made an homage. And then we tried to rewrite it, but we kept it because we couldn’t come up with anything better. Because Arrested Development is amazing.”

His wife remembers things slightly differently. “I will say that I think I wrote that line and I hadn’t seen the show — but that sandwiches are a very big part of our writing experience…We were always eating bagels when I was writing these lyrics.” In fact, Anderson-Lopez jokes, “if I could have put more sandwiches in, I would have.”

Downplayed musical numbers or no, one thing’s for certain: Disney isn’t shying away from pushing Frozen as a major addition to its canon. While in Los Angeles for the film’s premiere, the Lopezes visited Disneyland and were tickled to find the sunny park filled with icy tie-ins to the film. “You’ll see little kids dressed as Anna and Elsa, and I’m thinking, ‘How did they see this movie already?'” Anderson-Lopez laughs. And even though the movie’s promos don’t focus on their songs, Frozen‘s tunes have already been awarded a place of honor in the California Adventure park’s nighttime water show, The World of Color. “We sat through the rain — we bought those Mickey ponchos and sat in the rain to watch our songs on water,” recalls Anderson-Lopez. “You have to pinch yourself and say, ‘How did we get here?'”

“It’s one of those dreams you don’t have as a kid,” her husband adds, “but you’re really glad when it comes true.” Hmm — sounds almost like a line from a song.