Words: Ali Shutler.Photos: Frances Beach.

Fall Out Boy set out to roll back the clocks on Friday night at London's O2 Arena. We know what you're thinking: a pop-punk band relying on nostalgia? How original. But Fall Out Boy have always been more ambitious than that, and tonight's show proved that time and time again.

The band's impressive, varied back catalogue has always been driven by a need for reinvention, but recent album 'So Much (For) Stardust' saw them finally take a moment to reflect and bring all those different elements together. On it, the urgency of their hardcore punk beginning sits neatly alongside grand moments of theatrical rock and roll and the need for community. It's a celebration of the band and their refusal to do what's expected. Tonight's gig is no different.

Rather than leaning on their many breakout anthems, the show is a showcase for how wonderfully weird Fall Out Boy are. They open with a big swing from each of their three eras – 'Love From The Other Side', 'Sugar We're Going Down', 'The Phoenix' – before diving deep. A trio of songs from 2003's debut album 'Take This To Your Grave' are delivered under a lighting rig that makes the giant stage feel like a basement club, but the hammering tracks never feel out of place in the arena.

'Bang The Doldrums' and 'Golden' from 'Infinity On High' are played instead of 'Hum Hallelujah', 'Folie A Deux''s 'Headfirst Slide Into Cooperstown On A Bad Bet' is aired instead of 'I Don't Care' or 'America's Suitehearts'. These tracks might not be how FOB made it big, but these deliciously odd tracks are why they're still so beloved.

The energy never dips either, with breakout anthems like 'Thnks Fr The Mmrs' getting the same reaction as old skool deep cuts like 'Disloyal Order of Water Buffaloes' and new album tracks 'Fake Out' and 'What A Time To Be Alive'. "The world's always been chaotic, but getting to sing these songs together is really special," says Pete.

Openers PVRIS take a different approach. New album 'Goddess' saw the band refuse to rely on legacy as they once again shifted away from the dark, brooding pop-rock that made them such a welcome addition to the scene with 'White Noise' in 2014. Instead, they toyed with industrial metal, shimmering dance and arena rock'n'roll. Tonight, a bulk of their set comes from that brilliant album, which seems purpose-built for these massive gigs.

There's a newfound confidence to the band as well. On previous tours, the band have kept things delicate to allow Lynn Gunn's vocals space to shine, but tonight, they make a furious, playful racket. There's a stuttering breakdown during 'My House', 'Hype Zombies' channels both Deftones and Rage Against The Machine, while the acoustic 'Anywhere But Here' is backed by blossoming soundscapes and gets a little Radiohead in the outro. Rising to meet the challenge, Lynn sounds incredible whether she's snarling, screaming or singing, and it looks like she's having fun with it as well. PVRIS have always been a great live band, but this is on a whole other level. Bringing together all the jarring influences they've always pulled from, this is an astounding showing of the vibrant band PVRIS have become.

Fall Out Boy's Patrick Stump also wrestles with his own past onstage at London's O2. "I don't tend to talk onstage much; I don't tend to take the stage very much by myself," he explains, sitting alone at a piano. Pete apparently puts him up to it every night, "so let's see how it goes, I guess," continues Patrick, before immediately covering Queen's 'Don't Stop Me Now' flawlessly. Their own soul punk 'Golden' and the Elton John-featuring 'Save Rock & Roll' quickly follow.

There's a wonderful sense of fantasy to tonight's show. A giant dog's head appears at one point; there are bubbles and a rotating starfish, as well as a wise old oak tree. A Magic 8 ball is used to dictate part of the setlist, while Pete disappears into a piano after a moody 'Baby Annihilation' and appears at the over end of the venue for 'Dance, Dance'. As well as being wonderfully entertaining, there's a bigger purpose to this sense of wonder.

"A lot of 'So Much (For) Stardust' is about the monotony of the human existence as we trudge slowly to death, which is not that great to talk about," admits Pete midway through their set. The other part of their latest record is about encouraging the part of you that "existed before you knew what the rules were," he adds, reflecting on playing The Floor Is Lava as a kid and bending the rules at will.

"We don't tell people that the stuff they make is fucking awesome. TikToks, bracelets, art, or just imagining being a football player, that's incredible. The weirdness of [dreaming], and all of us being a little bit different but coming together, that's very important," he continues. Right on cue, a fan throws a handmade doll of Pete onto the stage that Andy quickly collects and hands to him. "This is definitely strange, but in a good way," he beams.

After years of wrestling with being outsiders, Fall Out Boy are now just proud of how weird they've always been.