JAZZ Ernest Ranglin Jazz Cafe, London

That the guitar is really a percussion instrument in disguise should surprise no one who's seen a flamenco player knocking at the door of his instrument, or heard James Brown's Bobby Byrd beat the strings as if they were talking drums. Jamaican guitarist Ranglin picks at his fretboard so closely to the bridge that the resulting noise sounds like woodpeckers hammering away at a bough. The strings are tamped so tautly that the instrument's tonal palette begins to resemble that of a marimba, until Ranglin relaxes the action to move into more conventional chordings, intersecting big fat jazz licks from the classic Fifties school of semi- acoustic masters like Wes Montgomery or Grant Green. Mainly, though, he is content to skank, supplying the supple rhythm for an easy-loping reggae pulse, and decorating the beat with loose, scatter-shots of Studio One chugga-chugga rhythm-figures joined to proto-Memphis funk.

It's quite a performance, and though Ranglin is hardly the most visually arresting of performers - he's a shy, professorial, old-time islander in his sixties - his music really does speak volumes. Thirty-odd years ago he made Island Records' debut album, and Below the Bassline, his striking set for the same company last year, was one of the most enjoyable jazz records in an age. In between, Ranglin masterminded the first Jamaican worldwide hit, with Millie Small's "My Boy Lollipop", which he arranged, and, so the story goes, helped to invent reggae when as an influential studio musician he slowed down the pace of ska to create a new, rootsier dance style. Throughout, he has always played jazz for preference.

Accompanied by his Jamaican quartet, Ranglin ran through the album's revision of well-known reggae tunes by Toots and the Maytals, Burning Spear, and the Congos to the continual delight of an audience including many friends and associates from way back when. Though his demeanour is self-effacing in the extreme, and there was no one in the band to seriously threaten his musical supremacy, Ranglin more than made the guitar talk. Indeed, at times his sleek, fat-bellied instrument seemed to articulate the whole vocal heritage of post-war rhythm and blues from America, the Caribbean and Africa (there's more than a hint of Nigerian ju-ju music in his sound). While the easy grooves of skanking might be the name of the game, Ranglin's sublimely percussive guitar is clearly knocking on heaven's door. Phil Johnson