Robert Plant & Alison Krauss, Wembley Arena, London

The staging is distinctly understated: save for a gold curtain that unfurls before the closing number, Robert Plant and Alison Krauss's show is almost completely devoid of visual distraction. Just a few rugs, a discreet curtain backdrop, and a couple of modest screens either side of the stage.

Even the band have the low-key demeanour of upscale bouncers. But although they don't make any flashy moves it's sometimes hard to tell whether it's Buddy Miller or Stuart Duncan that's picking out a specific guitar solo they have the lived-in look of great character actors. Bassist Dennis Crouch bears a resemblance to the late, great Peter Boyle; and bandleader T Bone Burnett could be a riverboat gambler from some Anthony Mann Western.

The important thing is that they're all masters of their instruments, none more evidently than drummer Jay Bellerose, a constant blur of movement as he employs a wealth of techniques to draw every last breath of drama out of each song. This isn't drumming, it's inhabiting the songs so intimately that they burst vividly into life, whether he's dashing off a frisky second-line shuffle behind Burnett on "Bon Ton Roulay", driving the bold, dynamic shifts of a bluegrass "Black Country Woman", or draping cloths over drumskins to dampen the beats on a slow, sultry "Black Dog".

Then, of course, there are Plant and Krauss themselves, a pairing whose unlikeliness is still evident in the occasional slight twinge in their harmonies. But all the best musical couplings have this kind of unexpected eccentricity about them, and this one works magically, from the sly warmth of "Rich Woman" to the rockabilly "Gone Gone Gone", reaching its apogee on a tremendous "Please Read the Letter".

For much of the show, Krauss leaves the violin duties to Duncan to concentrate on singing. And what a voice she has! Her keening wail on "Trampled Rose" is spine-tingling, quite supernatural in its haunting purity, while her delivery on "Sister Rosetta Goes before Us" and "Through the Morning, Through the Night" stands as testament to the one-inch-punch emotional power packed by the gentlest of voices. "Down to the River to Pray" gets a particularly warm reception, too.

Plant, meanwhile, proves there's more to his game than the shriek of yore, with the warm vocal caresses of his harmonies interspersed with more rousing bonhomie on "Fortune Teller", before he dives bravely into the maelstrom of despair that is Townes van Zandt's "Nothin'". A pertinent reminder that sometimes, some music demands to be taken seriously.