Miley Cyrus has spent her entire life growing up in public. She has been a teen pop star, an “off the rails” young woman, a collaborator with Wayne Coyne of the Flaming Lips (though it sometimes felt that Coyne was serving chiefly as her muse).

All these conflicting feelings, memories and trajectories are given a rock ’n’ roll gloss and spat out in thrillingly day-glo form on her new record, Plastic Hearts.

As is often the case with great pop LPs, the album is full of contradictions. It is completely scattershot – one moment Cyrus is collaborating with Billy Idol (‘Night Crawling’), the next crooning over a remix of Stevie Nicks’ ‘Edge Of Seventeen’.

And yet this is also a project with a clear through-line. Cyrus knows who she is now and Plastic Hearts is a celebration of her evolution into a clear-eyed pop visionary. It is the most coherent mess you’ll hear all year.

Hannah Montana and teenage fame are, of course, the contexts she can never escape as a grown-up artist. However, the immediate backdrop to Plastic Hearts is her marriage in 2018 to Liam Hemsworth.

“I wore a dress on my wedding day because I felt like it, I straightened my hair because I felt like it,” the pansexual Cyrus said at the time of the knot-tying. “But that doesn’t make me become some instantly ‘polite hetero lady.’”

Eight months later, the relationship was over. Confirmation arrived with snaps of her in a romantic clench with reality star Kaitlynn Carter.

She doesn’t directly address her personal travails on the new LP (there was already a quasi-official break-up single, ‘Slide Away’ – which has nothing to do with Oasis). Nonetheless, Plastic Hearts is audibly the work of a musician emerging from a storm and entering a period of reflection and personal growth.

Mixed in with that is her palpable desire to breath vitality into what is widely considered the most moribund genre of them all: rock ’n’ roll. This is spelled-out in the deluxe edition of Plastic Hearts via her covers of Blondie’s ‘Heart Of Glass’ – slowed down and steeped in guitars – and The Cranberries.

Here the significance is surely that she is doing ‘Zombie’ rather than a more ethereal Cranberries highlight such as ‘Dreams’. Early Cranberries is the standard go-to for young bands citing Dolores O’Riordan as an influence (Beabadoobee, Weyes Blood etc). Cyrus, however, jumps straight to the Limerick icons’ grunge phase with an interpretation that is all about the riffs and the rage.

Is she pouring in whatever angst lingers after her split from Hemsworth? Who is to say? What’s beyond doubt is that this is a collection full of raw and ragged moments. You can hear it, too, on ‘Bad Karma’, her growling get together with Joan Jett.

“They say it’s bad karma bein’ such a heart breaker,” goes the chorus. “I’ve always picked a giver, ‘cause I’ve always been the taker.”

It’s wrenching and unforgiving – and a reminder that, when it comes to processing bottomless pain, rock is still the only genre in town.

This brings us to the wonderful irony around Plastic Hearts. Rock, we are told, is long past its sell-by date. Even the great new rock groups of the era seem embarrassed by the mythology created by their forbears.

The entire point of bands such as Rolling Blackouts Coastal Fever, Shame and Fontaines D.C. is that they don’t have any swagger and certainly do not wish to be on a pedestal. Humility is the new rock ’n’ roll.

This leaves a huge market gap for Miley Cyrus. On Plastic Hearts she swaggers the way the guitar gods from the primordial age used to. In 2020, when rock needs saving, who’d have imagined that the artist to do so would be a former Disney teen star? That’s the mixed-up world in which we live – and one in which Miley Cyrus has never been more at home.

• Plastic Hearts is out now.