He may look like Elvis, but this is Johnny and he just ain't rock'n'roll

The first thing to know about Peter Schaufuss's ballet The King is that, as the programme insists three times over, "This production is not endorsed by or associated with Elvis Presley Enterprises Inc". Like heck it isn't. The Elvis estate has done its heavyweight legal best to wipe this weird cultural hybrid off the map. "The official story - from choreographer Schaufuss - is that the copyright-holders suddenly objected to the use of certain songs, obliging him to cancel the show's run in Edinburgh and rewrite several numbers for the London opening. From the internet, however, you learn that Lisa Marie hadn't much liked the way the show depicted her father, and was threatening writs on that basis.

What the Elvis estate hadn't counted on was the tenacity of Peter Schaufuss and the creative thinking of his lawyers. Interviewed on Radio 4, Schaufuss declared he had completely rewritten the plot. True enough, the printed synopsis now spins some guff about Johnny, an Elvis-impersonator, and his girlfriend Debbie and his bass-guitarist mate Brian. But what you see on stage bears no relation to this banal scenario. It's clearly the story of Elvis, and I suspect Schaufuss has changed the show very little. Only when you rumble this, and give up trying to square the bloke in the rhinestone flares with Johnny, and the sleek, flicked-up Priscilla figure with Debs, does the show begin to make sense. Clever, clever Schaufuss. I think he's pulled a fast one.

Whether you applaud his coupling of ballet with rock'n'roll is another matter. To me, it's a mismatch: classical technique is about polish and finish, rock is all raw thrust and rough edges. And while the effect of an entire chorus of biker-jacketed guys executing immaculate quintuple-spin jumps is exciting, butwhen the same roughnecks whizz about with their arms held à la seconde it jars.

Schaufuss does better when he homes in on ballet's fetish potential. When Elvis (sorry, "Johnny") enlists with the US army, a big ensemble set to Marlene Dietrich's jaunty "Muss ich denn" has lines of girls in combat fatigues and army caps squad-bashing on pointe - an image so outrageously at odds with itself that it's both funny and very sexy. And again, Lisa Probert as the mini-skirted Priscilla (for legal reasons read "Debbie") character nicely harnesses the minxy qualities of pointework to sketch out her seductive and flighty nature. Her first slinky duet with Juan Rodriguez's big hunk'o'love is the most engrossing piece of extended choreography in the show.

Those who know their Elvis are sure to find more oblique biographical references than I was aware of. Given the legal subterfuge, this acquires an element of rock'n'roll trainspotting, which can be taken to bizarre extremes. The woman next to me was convinced that the nude duet at the beginning - to the strains of Also Sprach Zarathustra, the music Elvis used to fanfare his gigs - was Elvis and his twin brother being born, even though one of the dancers was a woman.

By and large, this is a big, glitzy, easy-on-the-eye entertainment, superby designed and lit (by Steven Scott) and danced by a handsome company. Juan Rodriguez does look a bit like the King; he certainly has charisma and a mean high extension, though how this balletic accomplishment relates to the character is unclear. Purists of any persuasion should probably stay away. This certainly ain't rock'n'roll.

'The King': Sadler's Wells, EC1 (020 7863 8000) to 6 May