All images thanks to Valerio Berdini

Sometimes when a group who made their name on, or were regarded as, chaos incarnate get their act together it might feel like something is missing – but tonight at EarTH that's never the case for the Fat White Family. Given their propensity for discord it might come as a surprise to learn that what makes them so good on this chilly Monday night is a new-found professionalism and sense of unity. Saul Adamczewski is present for starters, part of a line of musicians who resemble a Slovenian 70s lower league football team who've just discovered speed and illegally imported glam rock records. This sturdy backing for a prowling Lias Saoudi open with 'Auto Neutron', the track that when this was just a young band with minds full of dreams and eyes on a fix, often evolved into a chaos that set the tone for the rest of a wild and fragmented evening, Lias getting naked, all of that, etc. They were energised gigs, but there's an inherent risk with that level of performance that the feral becomes the sole reason why people are there. When that happens the artist is forced to become their persona, to appalling consequences for their physical and mental health – and we all know that's exactly what happened here.

It's therefore thrilling that in a set loaded with the stand-out moments from their three albums (and those two imperious standalones 'I Am Mark E Smith' and 'Touch The Leather') the band still have that same power, but seem so much more together with it - indeed, they're becoming so well-drilled that they're starting to fill the hole left by the Bad Seeds as they move further into genteel old age. In the same way, The Fall might be gone, but Fat White Family are their greatest living descendants. Yet while Mark E Smith once exhorted his band to professionalism while conspicuously failing to show it himself, this new lean mean Fat White Family seem remarkably steady and, as an aside, they also remain an incredibly louche, sexually charged, homoerotic proposition, something that could never be said about The Fall.

This focus has given them a fair greater control over the dynamics that makes a rock show more than going to see a bunch of musicians play the songs. Paradoxically, the excitement is far greater with this newfound steely edge – tracks exploding into life, Lias in the crowd all of a sudden, handing out booze, the whole set executed with a determination and grit. There's even an interlude where Saul performs a couple of songs on his own that, though the curse of London gig chatterers that's blighting modern music does its best to dampen the vibe, is almost touching. Or is it? Because you're never quite sure with Fat White Family, who lyrically continue to explore the seamy underside of the British psyche and subvert the appeal and sexuality of rock & roll with songs that often manage to be both character studies and self-flagellation. Perhaps it's the Saoudi's status as mixed-race outsiders (as memorably misunderstood by Pitchfork) that give them this insight into the depravity of British masculinity, rock archetypes, and so on. In a time when most song-based guitar music is generic and beige, this band seem to be both a summoning and wallowing in wrongness. Much of what Fat White Family seem to be saying in their explicit daubings is that you to understand that the British establishment was Jimmy Savile as much as it is the Queen - recent revelations over Prince Andrew's connections to Jeffrey Epstein make a song like 'Cream Of The Young' only more timely. It might make us feel uncomfortable, but that (as we really shouldn't need to keep pointing out) is the job of art.

I think there are few better ways of really getting to grips with Fat White Family's obsession with the negatives within the self and society alike than purchasing Adelle Stripe's Sweating Tears With Fat White Family pamphlet for Rough Trade Books, in which an open and honest Lias and Saul give a frank account of their predilections, motivations, flaws and hopes. In it they nail the sense that, politically, sonically, aesthetically, Fat White Family are a band who are sincere (sometimes to the point of self-destruction) about what they do, but never earnest in that Idles "four pints and all the feels' punks" way that John Doran dissected the other week.

And of course, this far into their career, they've got a magnificent arsenal of tunes. The penultimate track is 'Feet', that rolling, disco-inspired banger with one of the hottest (not in the Zane Lowe way) videos of recent years, and it just sounds immense. Whether the band manage to achieve the same level crossover as their more hod-carrying cod-political punk rock contemporaries remains to be seen, but I'm not sure they'd entirely care. I certainly don't – for me Fat White Family are one of those rare groups that you can believe in and become utterly enthralled by. Their struggle continues, beautifully, with sweat and fire.