It never seemed to bother Val Doonican, but Blackalicious's Gift of Gab was worried about sitting down on the job: "I wasn't sure I could pull this off on a stool." He had a foot injury that his doctors told him was bad enough to jeopardise the tour. But it worked in his favour. Instead of the caged-animal school of stage roaming (Lateef the Truth Speaker was on hand for a spot of that), he was focused on the spot, and the crowd was drawn in.

It is worth getting close to Blackalicious. Their rhyming fills the gaping intellectual hole left behind by a lot of rap. Their music is also broad-minded, putting flesh on hip-hop's skeleton of bare beats and words. It has the wit of A Tribe Called Quest and the spirit of Michael Franti. Chief Xcel on the decks and backing singers Omega Brooks and Damu Quarles lift Lateef and Gab's rapping with a cappella vocals, spoken melodramas, brass sections, orchestras and the ghostly voice of Gil Scott-Heron.

As he built up a head of steam, Gab rose to his feet miraculously, as if he had been touched by a faith healer. He talked to the crowd, sometimes to pump them up, sometimes to say thoughtfully that it is time to stop the world derailing. You couldn't spot the gap between the chatter and the rapping, as he gently accelerated and took flight. There was every shade: speed rapping that almost sounded like a tabla, singing, Quest-like slow funky rap. And barely a swear word in sight. Instead of finishing with a bump at the end, on tracks such as Make You Feel That Way, Gab eased back into talking, by the end just repeating the title of the tune in a whisper.

Blackalicious are not afraid of a spot of showbiz, either. Alphabet Aerobics, a collaboration with Cut Chemist, had Brooks catwalking the stage holding up cards printed with all 26 letters. Gab gave a thought for each one while Xcel leapt through a musical alphabet. A long way from your average hip-hop vocabulary.