I don’t yet know what my song of the year is, but I can tell you without hesitation what the song I’ve heard the most is, albeit not always in its recorded version: the Oscar-winning Let It Go. Technically, the song from Frozen is sung by Broadway star Idina Menzel in the role of Elsa the Snow Queen, but as far as my seven-year-old daughter – who has been singing it several times a day for weeks – is concerned, it’s hers.

Like the snow in Frozen, Let It Go is everywhere, and it’s not disappearing without a fight. It’s the main reason why the Frozen soundtrack has been the No 1 album in the US for nine weeks and counting – Beyoncé only managed three – and a significant reason why the film became the highest-grossing animated movie of all time. On YouTube, where it sits alongside countless amateur cover versions, spoofs, supercuts and fan-made videos, the Let It Go sequence uploaded by Disney last December has attracted almost 180m views. Still, these mind-boggling statistics strike me less forcefully than my daughter’s unprecedented obsession. To her, an older sister at an age where boys are beginning to become a source of intrigue rather than irritation, and conventional Disney princesses are a prissy drag, it’s more than a song. It’s a glimpse of the future, a vessel for secret knowledge.

Reading on mobile? Click here to view Let It Go video

Critics are often accused of overthinking mainstream hits, but the songs that outstrip all expectations (Disney didn’t anticipate that Menzel’s original would eclipse Demi Lovato’s tamer pop version) always demand a closer look. One test of a truly great song is an ability to listen to it dozens of times without screaming. I’m not a musicologist (although this guy is), but anyone can understand why Let It Go is a bravura piece of musical storytelling: the nervous minor chords of the first verse, jumping to an emphatic major key with the line “Well now they know!”; the frantic, pulse-quickening syncopation of the bridge; the explosive leap of the chorus, mirrored in the animation’s rapid ascent; and the final imperious shrug of “The cold never bothered me anyway.” It’s uncommonly fast for a power ballad, too – 137 beats per minute – which is why it’s been recommended as a workout song and remixed, badly, into a club banger.

Let It Go is so undeniable that it changes the direction of the movie. When Kristen Anderson-Lopez and Robert Lopez were commissioned to write "Elsa’s Badass Song", the Snow Queen was a more conventional villain, but the song’s emotional power forced a rethink. “The minute we heard the song the first time, I knew that I had to rewrite the whole movie,” said director Jennifer Lee. That’s pretty potent songwriting.

In the film, Let It Go is a moment of dark irony. Elsa’s liberation doesn’t just mean lifelong solitude but eternal winter for everybody else – although she doesn’t yet know it. Even before she realises the damage she’s done, her excitement is gleefully irresponsible: “No right, no wrong, no rules for me.” In one popular YouTube parody Elsa sings “Fuck it all," which is pretty much the gist of it. The viewer knows she’s wrong but gets carried away anyway.

I think this is why the song is so addictive for girls a few years away from puberty, already chafing a little at the parental reins. It serves as an aperitif for adolescence. Elsa’s leaving home and finding a place of her own (buck the house-price boom by building your own ice palace in minutes!), marking her rejection of social and familial pressure by swapping formal palace-wear for ice-minx couture.

Reading on mobile? Click here to view the Let It Go parody, Fuck It All

Slate’s movie critic Dana Stevens, who also has a Frozen-addicted daughter, has written about her “familiar sense of deflation every time that pulse-racing song culminates in a vision of female self-actualisation as narrow and horizon-diminishing as a makeover”. Like her, I usually dislike the makeover trope, but here it’s not designed to impress a man – it’s purely for Elsa. And this sequence isn’t a happy-ever-after resolution. It’s a moment of transition and upheaval which conveys the giddy, reckless buzz of expressing yourself without considering the consequences. At such moments, teenage girls are not famed for acting like feminist paradigms. Disney’s first movie without an unambiguous villain produces its first song to describe how young people really do behave rather than how they should behave.

I suspect girls like my daughter sense that the song’s emotional landscape is adolescent – somewhere over the horizon, not yet visible, but faintly palpable. The Lopezes have said they were “thinking from an emo kind of place”, inspired by the likes of Aimee Mann and Adele, when they wrote it. And, as Indiewire’s Sam Adams notes, thrilling yet terrifying superhuman powers have been used as metaphors for hormonal uproar elsewhere, for example, in Carrie and X-Men.

Outside the film, Let It Go is also a coming-out anthem for lesbian, gay, bisexual and transgender people: “Conceal don’t feel, don’t let them know/ Well now they know!” The lines “It’s funny how some distance/ Makes everything seem small/ And the fears that once controlled me/ Can’t get to me at all” could almost be from an It Gets Better video. “I was really excited to write an anthem that said, ‘Screw fear and shame, be yourself, be powerful,’” said Anderson-Lopez.

The titles of various international versions speak volumes about the different potential emphases: Let Out Your Secret (Arabic), Let It Be (Estonian), Let Go and Forget (Russian), Doesn’t Matter (Ukrainian), It Ends Now (Serbian), I Have This Power (Polish), I’m Free (Portuguese), Freed, Released (French) and, somewhat literally, Ice Heart Lock (Cantonese). If Pharrell’s Happy can be weaponised as a protest song, I wouldn’t be surprised if Let It Go found its mutinous calling one day, studded as it is with the language of refusal: “not”, “couldn’t”, “can’t” (twice), “no” (three times), “never” (four) and “don’t” (five).

To me, it means something else. Whenever I hear my daughter singing it, swept up in its vertiginous intensity, belting out the chorus as loudly as someone trying to call for help in a high wind, I feel a tiny premonition of loss. She doesn’t know it yet, but some day she will rebel, fight for her independence, do brilliant things, do stupid things, learn about her power and the dangers of power, and what she’ll be letting go of, as she should and must, is her parents.