One of the Green Day T-shirts on sale at the O2 bears the words: “No racism, no sexism, no homophobia.” These are the rules posted on the wall at 924 Gilman Street, the staunchly socialist all-ages punk club in Berkeley, California, where Green Day found their feet in the late 1980s before being shunned for the crime of being pop-punk sellouts. There are moments tonight when it feels like the countercultural spirit of Gilman Street is alive and well, like the ferocious performance of the title track from American Idiot, Green Day’s multi-platinum Bush-bashing 2004 rock opera, intensified by singer Billie Joe Armstrong’s throat-ripping roar of “Fuck Donald Trump!” There are also elements, like a man in a Halloween pharaoh’s headdress playing the saxophone solo from Careless Whisper, that would make Berkeley’s punk purists convulse with horror.
This fundamental tension is what makes Green Day more interesting than most arena-rock bands. Many pop-punk groups aim for a comfortable merger of the two traditions, but with Green Day the relationship is more complicated. They get their melodic craftsmanship from Paul McCartney, their conceptual ambition from Pete Townshend, their showmanship from Bruce Springsteen, their velocity from the Ramones and their ethics from the Clash. At any given point, one of these influences has the upper hand and tonight it’s mostly Springsteen. Green Day play for two and a half hours with a relentless, crowd-pleasing zeal that sometimes lures them towards the naff. Their wedding-band medley of Shout, Always Look on the Bright Side of Life, Teenage Kicks, (I Can’t Get No) Satisfaction and Hey Jude is every bit as corny as you’d imagine, but the crowd loves it just as much as their frenetic cover of a song by their underground Gilman Street contemporaries Operation Ivy. Green Day have somehow carved out a space where both make sense — where punk roots and showbiz hokum don’t cancel each other out.
The band seem more energised than at any time since American Idiot, and not just because Armstrong is clean and sober after a very public unravelling. For any band with a hefty back catalogue, each new tour’s set list is a way of reframing the past. It’s revealing that tonight Green Day play precisely nothing from their unloved 2012 trilogy of albums and only one song from 2009’s bold but unwieldy 21st Century Breakdown, yet two from 1991’s pre-fame Kerplunk. It’s almost as if the last decade never happened.
The impact of last year’s career-reviving Revolution Radio was magnified by the rise of Donald Trump, which reignited Armstrong’s appetite for protest. The chant of “No Trump! No KKK! No fascist USA!” that he debuted at the American Music Awards last November has become a permanent fixture of Bang Bang. He introduces Holiday, American Idiot’s most barbed track, with a cry of “This is a protest song!”, reciting the toughest verse through a megaphone while scanning the darkened arena with the bright white beam of a handheld spotlight.
If there were screens on stage, they’d probably feature Trump’s sour mug, but Green Day haven’t joined arena-rock’s hi-tech arms race. There’s just a series of backdrops, some run-of-the-mill pyrotechnics and the sight of the band themselves. Bassist Mike Dirnt is a gaunt punk-rock version of Kramer from Seinfeld; drummer Tré Cool a gurning slapstick schoolboy with a quiff that suggests he gets his hair dye from the same place as the Joker.
The improbably boyish Armstrong has a relentless urge to bond band and audience. A cynic might wonder if a 20,000-capacity arena branded by a mobile phone company can fairly be described as “our own little private underground”, or if the ticket holders in the private boxes really qualify as “all of the weirdos and all of the freaks” but Armstrong’s sincerity is disarming. He invites fans on stage to sing whole verses, solicitously coaching them before sending them diving back into the throng. After asking one disabled young woman to play guitar on Knowledge, he insists she keep the instrument. Green Day started out in a tiny DIY club dedicated to inclusivity and they honour that ethos as best they can on a stage this big. Combined with their numerous songs about misfits and outcasts, whether tender (Christie Road) or defiant (Minority), this makes Green Day a force for good in times like these. Never mind the medley.