ROCK / The gospel according to Eric: It looked like Clapton. It sounded like Clapton. But the credits belonged to Scrapper Blackwell and his colleagues. Giles Smith gets the blues

TO THE CASUAL eye, Eric Clapton's annual Albert Hall residencies must look like rock at its most pointlessly ritualistic. Every February, it would appear, he block-books the venue for a record-busting duration, packs in the punters, hits them with 'Layla', and goes home, via the bank, to rest up in time for next year. The truth is, some act of re-invention seems to take place in the intervening months, making the event's tireless cycling more than merely mechanical. And never has the re-working been so radical as this year, with the 'Rhythm and Blues' show.

Clapton arrived on stage in the usual swish of pricey tailoring, made the usual modest bow, cracked the usual smile to the front rows and received the usual standing ovation. So far, so usual. But the list of songs on the floor at his feet was abnormally gigantic. It seemed to have drifted in from an Andrex commercial; and on it, we would discover, were titles of blues numbers by Maceo, by Leroy Carr, by Jimmy Rogers, Muddy Waters, Howlin' Wolf. Nothing, though, by Eric Clapton. This year, he's taking the boldest risk of all - playing a selection of his old favourites, as distinct from a selection of the audience's old favourites of his.

Organised chronologically, the show works like a blues revue, leading you from the Twenties (a time before rock 'n' roll, a time, even, before Eric Clapton had started pitching up at the Albert Hall every year) forward to somewhere around the present. And what you see on the stage enacts a kind of evolution. The primitive figure on the seat at the start, hunched over an acoustic guitar, then sits back with a semi-acoustic and eventually develops into a biped and walks about the stage holding a slinky black Fender.

Around Clapton, the band comes and goes, forming a variety of splinter groups - guitar and piano, two guitars, guitar and bass with drums - and then finally coheres, complete with three-piece horn section, to get noisy for the concert's final half hour. It's a band built for the long haul. The figure in the double-breasted suit, blowing a gale through a harmonica, was Jerry Portnoy. The man on bass, just occasionally lifting an ankle and snapping his foot down on the beat, was Donald 'Duck' Dunn. The guy with the hair adding the flashy hi-hat parts to 'Hear Me Calling' was Little Feat's Richie Hayward. And meanwhile, Chris Stainton was seated behind the Albert Hall's grand, but somehow managing to waggle his fingers on the keys until it performed a passable impersonation of a bar-room piano.

Taken whole, the show is remarkable for ditching a fairly obvious commercial opportunity in the interests of throwing a few songs around. Unplugged, the album of the acoustic performance Clapton made for MTV, has been in the charts for six months. It was notable for broadening his audience still further and for revivifying even 'Layla', which, already looking badly bruised by over-use, had been beaten to within an inch of its life by saturation car advertisements.

But at the Albert Hall, Unplugged went unplugged. From the album, Clapton reproduced Big Bill Broonzy's 'Hey, Hey', performed as an intricate acoustic guitar duet with Andy Fairweather Low, and threw in Robert Johnson's 'Walkin' Blues', albeit on electric instruments, and left it at that. During a quiet moment between songs, a lone protesting voice rose out of the audience, singing 'Lay-lurr', but even this sounded simply cheeky rather than genuinely disappointed. 'Next year,' said Clapton. 'You'll have to be patient.'

If the show is a journey through the blues, then it isn't afraid to venture on to the tougher terrains. In fact, it's the sort of journey where you'd be well-advised to carry water with you and inform people when you're setting out and when you expect to be back. Introducing his first number, 'How Long', Clapton carefully credited its original performers. The quizzical silence which descended on the audience indicated that, right up until that minute, many would have said, if pressed on it, that Scrapper Blackwell was a second-hand car dealer.

Clapton was in a new teaching role here, and he's probably never talked so much between songs. His voice held up steadily during them as well. Already steeped in mournfulness, there was no point at which it sounded uneasy with the dark contours of these numbers. Unplugged might have popularised his acoustic guitar playing and opened his audience to settings in which they could hear the quiet tap of his foot on the floor. But even so, you sensed the moment most people had been waiting for came at the start of Muddy Waters' 'Long Distance Call', when Clapton plugged in and launched a long, loud note down the auditorium.

At the close, Clapton looped back to the start and played Bessie Smith's 'Ain't Nobody's Business', by way of showing us how far we had come. In some respects, we hadn't come very far at all, really - same three chords, same tendency towards life-hardened melancholy in the lyrics. Yet the show had demonstrated how, for all its growth and its off-shoots, rock music is still flexible and various down around the roots. And among the evening's more peripheral achievements, Clapton had managed to play the blues for an hour and a half and, in all that time, we only once heard the line, 'Well, I woke up this morning . . .'

(Photograph omitted)