ROCK; Swamp doctor's heap good medicine

THE LAST time Dr John was in Britain, there were whispers that it might indeed be the last time. Thirty years of more pharmaceuticals than the average doctor ever sees had taken their toll. Soon his wholly deserved title of "living legend" would be only half right. He has either worked some voodoo magic in the intervening months, or his renunciation of heroin has done the trick, because Mac "Dr John" Rebennack is alive and well and playing in London. When he strolled to the grand piano in Ronnie Scott's on Monday, he was supported by a cane (despite being only 55) and his beard and physique were those of a Louisiana Santa Claus, but he was clear-skinned and dapper in his black suit and trilby.

Long live the King of New Orleans. Songwriter and piano genius, Dr John is the kind of person who turns up on records by Lennon, the Rolling Stones, and Sonny and Cher, and on TV shows hosted by Jools Holland. (Sure enough, there at the next table, in the orange glow of the lamps, Holland was sucking on a cigar.) His rhythm'n'blues is so rolling, atmospheric and swampy that even those of us who have spent no more than a couple of nights in the French Quarter get the urge to start using words like hoodoo, bayou and gumbo.

Dr John's latest album, Afterglow (Blue Thumb), focuses on standards of the Forties and Fifties, but it's spoilt by a showbiz orchestra that varnishes over his shaggy greatness. Tonight, it's just the good doctor and his trusty seven-piece band - they're all New Orleans legends, or deserve to be. The improvement is immeasurable.

One of his own compositions, "Walk on Gilded Splinters", stole the show. You could simply put it down to "soul", or you could be more technical and sift through the stew - indeed, the gumbo - of spooky backing vocals, shuffling maracas, menacing piano, bright guitar, and that effortlessly deep, cracked voice that all rock singers wish they had. Whichever: I'll never be able to listen to Paul Weller's cover version again.

G Love & Special Sauce, meanwhile, who played in London's Electric Ballroom, wish they were from New Orleans. Special Sauce are two hairy fellows, one who plucks complicated jazzy double bass, the other who rattles round his drum kit. G Love (no relation, I believe, to Courtney) is a loose- limbed, likeable dude who strokes a trickle of notes from a tinny guitar that would fall to pieces at the sight of an effects pedal. He also plays a wheezy harmonica, and sings with an expression of beatific pain, as if he is having an age-old itch scratched. His accent is such that the title of their new album, Coast to Coast Motel (Epic), is "Coda Coe Moe Dale" by the time it escapes his mouth. The group call their slippery sound "ragmop". Sadly, they actually come from Philadelphia and Boston; and G Love looks nothing like Dr John and a lot like the dark- haired one from PJ & Duncan.

Still, their youth can only be a boon, as they update the music that inspired them. The last element of their sound is Love's ramshackle rapping. As modern blues goes, this fusion of old and new is more heartening than, say, Robert Cray's technical flash, particularly on the single "Kiss and Tell" and a delicious rendering of the Beatles' "Help". If only they had more melodies like those to take the place of the repetitive grooves and bass solos. Music for a meander on a hot, pollen-heavy day.

Another post-grunge American band is Rocket From the Crypt, and if you had to guess what they sounded like on the evidence of their name alone, you'd be right. A San Diego punkabilly combo, you'd say, taking their cue from the Cramps and the Ramones. And you'd probably add - again correctly - that their new album is called Scream, Dracula, Scream! (Elemental), that they trade under the names of Speedo, ND, Petey X, Atom, Apollo 9 and JC2000, and that they dress in identical black and silver shirts.

Speedo is the creosote-voiced singer, who has the spirit of the young Elvis in the body of the old Elvis. "You're gonna see one of the best shows of your damn lives, either that or your money back," he declared, Southern preacher cum fairground barker, to the crowd squeezed into the London Garage. And, responding to some applause: "Thank you. I appreciate the attention, that's why I'm here." Now this is an attitude that many a young British band could learn from. Indie hopefuls tend to perform so grudgingly you want to apologise for dragging them away from their dressing rooms. Rocket From the Crypt play their breakneck thrash for - dare I say it - fun.

However, whether British bands - or anyone else - have much else to learn from RFTC is unlikely. Rather, they could do with some songwriting lessons themselves. They're invigoratingly loud and fast, but so's Concorde, and you wouldn't want to listen to that for an hour. A couple of tunes suggest better things: the angular riffing of "On a Rope", the echoes of Motorhead-with-a-brass-section in "Born in '69''. Otherwise, an ideal excuse to be jingoistically patriotic about the state of contemporary pop.

G Love & Special Sauce: Manchester Hacienda (0161 236 5051), tonight; Glasgow Garage (0141 332 1120), Tues; Leeds Irish Centre (0113 274 2486), Wed; Birmingham Foundry (0121 643 6843), Thurs. Rocket From the Crypt: Nottingham Clinton Rooms (0115 941 7709), Mon; Edinburgh Venue (0131 557 3073), Tues; Manchester Hop & Grape (0161 275 2959), Wed; Newport TJ's (01633 220984), Thurs; Astoria 2, W1 (0171 434 0403), Fri; Leeds Duchess (0113 245 3929), Sat.