Cheltenham-born, Bristol-based non-binary artist Grove and their on-stage accomplice, ace of bass EJ:AKIN, are dressed like cybergoths to support Bob Vylan in Cardiff – and it’s not just the neckware that’s spiky. The feral mash-up of dancehall, UK garage and industrial punk is – in Grove’s own words – “dark and dutty”, like a raging Missy Elliott getting her freak on to The Prodigy’s Breathe in a grimy cellar club.

For Grove, music is evidently both a means of coming to terms with and expressing their identity – whether on Black, written after the statue of slave trader Edward Colston was torn down and tossed into the harbour, or Sticky, which deliberately queers dancehall’s aggressive heteronormativity – and a loaded gun with which to take shots at everyone from energy vampires to unscrupulous landlords and wack boyfriends. The way that new polemic Stinking Rich Families shifts up several notches mid-song suggests that their best is still to come.

When headliners Bob Vylan arrive on stage, after a carefully curated playlist that sees Abba’s Money, Money, Money followed by Pink Floyd’s Money, they appear to be under the misapprehension that we’re still in need of a warm-up. Meditation and light stretching done, the duo duly treat the sold-out crowd to a most invigorating punk/metal workout, swiftly turning the room into a sauna. Frontman Bobby Vylan – clad in sportswear if not in lycra (by his own admission, he looks like John McEnroe) – assumes the role of Mr Motivator, urging the audience to “wage war against the state” (Bait The Bear).

As this might imply, Bob Vylan are a middle finger defiantly extended in the face of the Establishment – a Rage Against The Machine de nos jours, born and raised in a Britain that tries to erase their members’ existence. New album Bob Vylan Presents The Price Of Life couldn’t be more timely, and – as a record that was written, produced, mixed, released and even partially distributed by the band themselves on the way to cracking the Top 20 – it’s made history. Little wonder the pair are so proud.

In Bob Vylan’s world, blunt-force slogans and messages are very much the order of the day. “I heard you want your country back,” spits Bobby, flailed by his own dreads like a self-flagellating penitent. “Shut the fuck up.” There’s no room for subtlety, niceties or conciliatory gestures – Take That demands that you take sides, and Pretty Songs, during which he brandishes a baseball bat, admonishes pacifist punks for advocating non-violence: “No liberal lefty cunt is going to tell me punching Nazis ain’t the way.” No pain, no gain – as Mr Motivator might say.

Amid the carnage, Bobby makes the time to pay touching tribute to both his bromance with bandmate Bobbie, who is drumming despite having to wear a knee brace, and the venue across Womanby Street. The Moon was one of the first places to pay them properly, arranging food and accommodation, at a time when they were used to travelling by Megabus (and didn’t have to lug about the fruit machines that flank them on stage tonight). It’s impossible not to see the band’s trajectory as a powerful testament to the enduring value of grassroots venues.

Bob Vylan don’t scream “Fuck you I won’t do what you tell me”at absolutely everyone; they make an exception for Clwb for being so accommodating by respecting the 10pm curfew (“We don’t make the rules but sometimes we have to follow them”) – though only after Bobby’s given the health and safety person kittens by inviting half the audience to join them on stage for Wicked & Bad.

Formidable pugilists righteously fighting the corner of the maligned and marginalised, Bob Vylan are a product of our times – and a band at the top of their game.

Clwb Ifor Bach, Cardiff, Tue 17 May

words BEN WOOLHEAD photos HANNAH NICOLSON-TOTTLE