The Fall / The Magic Band, Royal Festival Hall, London

A few minutes into The Fall's opening number, Mark E Smith saunters on to the voluminous stage of the Royal Festival Hall, drops his jacket by the drums and sets about dismantling his mic-stand. A dream joint billing of two cult bands it may be, but for Smith it's business as usual, and over the next hour he sets about recreating the off-hand menace of a Fall gig by cuffing his bass-player, twiddling with the amps, poking mics into the drumkit and delivering a three-note keyboard solo with his hand behind his back, his body corkscrewed, like some malevolent modern-dress Richard III.

In his workaday blue shirt, grey trousers and shiny black shoes, Smith cuts the gloriously uncharismatic figure of a coach-driver on a fag-break. His vocals are a challenging bawl of falling vowels, words indecipherable beyond gut recognition, but Smith on stage remains a man with presence, toying sardonically with audience expectations. You can almost see him smile, but he doesn't, quite.

The latest version of The Fall delivers a stripped-down, pounding set dominated by material from last autumn's Country on the Click. There's a rousing rockabilly threesome in the middle - "Mr Pharmacist", "F-Oldin Money" and a ramshackle cover of "Walk like a Man" that's as loose as a torn string vest - before the band dive into "Theme to Sparta FC" and, for the closing number, a surprise resurrection of "Mere Pseud Mag Ed".

The Magic Band open the second half of the bill with the R&B nostalgia of "Diddy Wah Diddy" before segueing into an entirely different universe with "Smithsonian Institute Blues", from the era of Lick My Decals off, Baby. The drummer John "Drumbo" French is the band's wild-eyed front man, in white hat and trench coat, and thankfully his adoption of Captain Beefheart's mantle is a convincing one.

Drumbo and The Magic Band fill this music to the brim, and for the generations who have only ever heard the records - the Captain himself abandoned ship more than 20 years ago - it is a thrillingly visceral experience to hear the likes of "Click Clack" and "Sun Zoom Spark" in the flesh.

The Magic Band are crack players; what elevates them high above the rank of tribute band is their shared history in the making of this extraordinary music. Beefheart may have been the dominating force and composer, but it was The Magic Band who turned his directives into music that could be played. All this concert lacks is the unpredictable electricity of the Captain's presence. Like Smith, Beefheart would probably have been more interested in testing than fulfilling audience expectations.

But fulfilled they are. Drumbo's exuberant vocal performances frame the intense instrumental heart of the set, which draws on Trout Mask Replica and the likes of "Abba Zabba" and "Alice in Blunderland". They are more sound-sculptures than songs, their skewed dynamics reinvigorated by the physicality and zest of the musicianship. The Magic Band may once have been half-starved freaks living on mung beans, but a lifetime later they are seriously heavy dudes - less old farts at play; more a classic band playing at the top of their game.