The Black Crowes, Brixton Academy, London

The Black Crowes believe in a utopian sort of Seventies rock, a hard-played, hard-lived, freak-friendly style somewhere between The Allman Brothers Band, The Faces and the mid-period Stones at their most decadently loose.

Chris Robinson, who with his brother, Rich, has just hauled the band back together after some time away, fills the stage with such idealism. From the Persian rugs to the pulsing purple-and-red lights, he has turned the Brixton Academy into a luxurious hippie crash-pad, circa 1969. And as he prances towards us, you can tell he is trying to channel spirits as diverse as Otis Redding and Robert Plant. Much as Wynton Marsalis views jazz as a fixed heritage that needs to be preserved and passed on, so the Crowes do with rock's most debauched period.

It's fun for a while, helped by the high quality of the playing, which blasts to the rafters, bolstered by their new second guitarist, Luther Dickinson, of the North Mississippi Allstars. The notion that this first UK gig in three years will be a run-through of their new album, Warpaint, is ignored, as Robinson prefers to play long, gut-bucket blues notes on his harmonica on "Black Creeping Moon". For "Walk Believer Walk", he tries on the ghost of Otis's Southern soul, faithfully hitting high, extemporised notes.

The Crowes' early days, when they were little more than a Faces tribute act, have been replaced with a a Southern-fried version of Gram Parsons's Cosmic American Music. But other problems remain, and Chris Robinson is chief among them. Like Primal Scream's Bobby Gillespie, he is an acolyte of the great rock and soul stars but has been denied their attributes. Wispy and loose-limbed, he essays the campery of Robert Plant and Rod Stewart, but lacks the guts, substance and risk-taking that made them extraordinary at their best.

As when the drummer, Steve Gorman, tries a long drum solo, like Led Zeppelin's John Bonham, the difficulty of pulling such tricks off truthfully is made clear. It's too earth-bound, and hide-bound, to be cosmic. The band are better served when the spotlight falls on Chris Robinson alone, playing acoustic guitar on "Morning Song", before the band fall in, honkytonk-style, behind him.

For all their good heart, the Crowes' lack of tunes and original thought wears thin long before the end.