It has become increasingly difficult to prise Malian guitarist Ali Farka Toure away from the rural life in his home village of Niafunke. "Music is very important to me, but my profession is agriculture," says Ali, who spends most of his time irrigating chunks of the Sahara desert. He doesn't see music as mere entertainment, more as something that grows organically out of the land, which is why putting him and his band in a formal concert hall is always going to feel somewhat stilted. In his Malian French, he explained that he didn't plan to come back to London, and would be handing on the baton to his long-time music pupil and guitar player Afel Boucoum, who played the evening's opening set.

Still, having dragged himself onstage and plugged in his guitar, Ali at least seemed to be enjoying himself. He'd frequently let out a bark of laughter as he unleashed some particularly fiendish foray up the fretboard, while the call and response interplay between Ali and his backing vocalists swayed back and forth like a cobra coiling itself for action.

Ali has developed his musical style almost entirely untainted by outside influences - although he did win a Grammy for his collaboration with Ry Cooder on Talking Timbuktu - so its similarities to Mississippi blues is uncanny. His songs were often slow, mournful and infinitely weary, with only some modal scales and keening vocal lines to suggest this music was looking east before it went west. Elsewhere, he applied his ringing, metallic guitar tone to springier tempos, peeling off jangling melodic lines bizarrely reminiscent of Merseybeat and The Byrds viewed through the freeform prism of John Coltrane. Although I don't suppose that's how he hears it.

Boucoum's set shed a different light on the sounds of the Niger river. Where Toure's band (featuring several of the same musicians) appeared in simple shirts and trousers, Boucoum's team appeared in a dramatic assortment of hats, cloaks and capes. Their best pieces were constructed around relaxed but faintly menacing tempos, stretched over loping basslines and measured out in clattering cross-rhythms. Boucoum's guitar playing is stringy and nagging where Toure's bubbles effervescently, but it makes a perfect fit with the long, slow currents of his songs. I reckon Toure's right, though - this music wasn't designed for the Barbican Hall.