Isaac Hayes / Forum, London

If you think "Walk On By" is just a pop song then you should hear it get the full Isaac Hayes treatment. OK, so Dionne Warwick's 1964 recording was, without doubt, a benchmark performance, and the Stranglers turned it round pretty well with their version 14 years later. What Hayes does, though, is make you forget that a song has a beginning, a middle and an end. Instead, he allows the composition to kind of slowly infuse. After all, there's plenty of tune, so why hurry? As the man himself might say with a shrug "It's all right, we've got all night." At his Forum appearance, the process took around 16 minutes. Isaac Hayes sat relaxed at the piano while the guy with the electric guitar took centre stage and produced some sexual, languid sounds to set the tone. A full orchestral backing band hovered behind, waiting, as the guitar gently thrusted and surged, until finally becoming a spent force. Only then did the deep soul voice at last feel ready to sing.

"If you see me walking down the street," he began "and I start to cry, each time that we meet, walk on by." Simple words, but the master of emotion did more than just entreat you to walk on by. He begged and implored you as well, over and over, until his supplication became almost too much to bear. Yes, he'd got it real bad. By this time the other musicians and backing singers had further developed the motif, with the song eventually culminating in a duel between the drummer and the percussionist. At the end, there was just Isaac Hayes, sitting still at his piano, smiling. The legend looked cool in dark glasses and leopard-skin shirt, and the notes he played were exquisite as cut glass.

Unfortunately, the orchestra wasn't a real one. It was all done with banks of synthesisers operated by keyboard wizards. There were no strings and no horn section, which some members of the audience found a little disappointing. True, the joint was jumping by the time they'd worked through "Joy" and "Do Your Thing", but maybe it was a little too far from Memphis, where Isaac Hayes began all those years ago.

He told a plaintive story about being a young musician in the days of segregation. How the band was separated from the audience by a railing. How he could sing "My Funny Valentine" for a girl in the crowd but never actually get to meet her. Even today, when he sang that song, he thought of her. These memories were interrupted by some insistent percussion driven by a guitarist's wah-wah pedal. The multiple keyboards intervened and here was "Theme from Shaft" in all its glory. A reminder that Isaac Hayes is still very much where it's at.

Magnus Mills