ROCK / Will the real Eric stand up?

'AND HERE'S another of Jimmy Rogers' songs . . .'

'What about Eric's songs?'

'What about Eric?'

'Yeah . . . where is Eric?'

The sardonic conversation going on as Eric Clapton and his musicians launched into Friday evening's 17th 12-bar blues was merely an exaggerated expression of a general puzzlement that gripped large sections of the multitude for whom an annual pilgrimage to the Albert Hall is one of the few fixed points in a changing world. On the ticket it clearly said 'Eric Clapton and His Band: Rhythm and Blues', but for 20-odd quid many among the assembly clearly felt that the genre definition should be expanded to include the likes of 'Wonderful Tonight', 'Layla' and 'Tears in Heaven' - in other words, the gentler, sweeter songs with which Clapton has captured an audience beyond your basic blues and rock fans.

Indeed, that very morning Clapton had flown back from Los Angeles, where he had accepted no fewer than six Grammy awards, the US recording industry's Oscars, for achievements associated with Unplugged, the live-in-the-studio acoustic album which has given him the biggest success of his 30-year career. Record of the year, album of the year, song of the year, best male pop vocalist, best male rock vocalist, best rock song: no one else got much of a look-in.

The fact that Clapton is 47 years old is being taken in some quarters as an indication that the rock phenomenon is over and done with. This may or may not be true, but in any event it does scant justice to a man like Clapton, who - in his fifth decade - is currently doing the best work of his life.

I used to be sceptical about Clapton, partly through a generalised distrust of white blues guitarists who borrowed wholesale from their black elders and betters and partly because, one summer night in 1966, he disappeared after a show at the Beachcomber Club, Nottingham, with a dark-eyed student teacher on whom I happened to be a bit keen. That was just before he left John Mayall's Bluesbreakers, the band with which he achieved quasi-divine status, and whose shade he evoked time and again at the Albert Hall on Friday.

Clapton's object with these shows is to anatomise the music that shaped him, and to give an idea of its development from the 1920s to the early 1960s. Didacticism and popular culture make uneasy bedfellows, but Clapton had designed this show with loving care, and much of it was as enjoyable as it was instructive.

First, with the help of Chris Stainton's piano and Andy Fairweather Low's second guitar, he explored the intimate, small-scale country blues of Big Maceo and Scrapper Blackwell: the music of the backroads, of turpentine camps and itinerant songsters. Richie Hayward, Little Feat's master of polyrhythm, arrived at the drum kit to propel the small group through the transition from the Mississippi Delta to the Chicago stockyards, best expressed when Duck Dunn arrived to add his bass guitar to 'Walkin' Blues', described by Clapton as 'a Robert Johnson song in a Muddy Waters style'. Then, as the band rose from their seats and were joined by the harmonica-player Jerry Portnoy for Muddy's 'Long Distance Call', the sound grew thicker and darker. Now we were in the prime years of electric Chicago blues, and the band produced exact versions of Little Walter's 'Juke', Jimmy Rogers's 'Blues Leave Me Alone' and Howlin' Wolf's ominous, clanking 'Forty Four'.

A three-piece horn section filled out the final sequence of songs from the catalogues of Bobby Bland, Freddie King and Buddy Guy: big-city blues, all vestiges of the rural past stripped away. The presence of Dunn made 'Born Under a Bad Sign' specially poignant: he played on Albert King's 1967 original, as a member of the classic Stax house band. Now Clapton was embarking on screaming, multi-noted solos, abetted by Buddy Guy himself on a closing boogie.

In the end, I had some sympathy with the dissidents. Here was a reincarnation of Clapton the blues impersonator, a far less interesting artist than the mature, thoughtful author of Unplugged, a chap who has spent half a lifetime working through his influences and will, if we're lucky, spend the rest of it proving that he really does have something of his own to say, after all.