THOUGH EVERYONE knows Jose Feliciano's wonderfully slack, slowed- down and jazz-inflected version of the Doors' "Light My Fire" - his big breakthrough hit 30 years ago - but most of us know little else. There is a vague memory of the "genius" tag with which he was once promoted, a heavy rep that sightless singers in the 1960s almost seemed to be burdened with as a matter of course. If Ray Charles was the genius of soul, and Stevie Wonder was, well, another one, Jose Feliciano was their Latin cousin, the blind Puerto Rican boy brought up in a family of 12 in Spanish Harlem who overcame adversity by singing and playing the guitar. The part of the story that we maybe didn't get, although if you were listening it must have been evident all along, is that Feliciano doesn't just play his guitar: he pretty much re-invents it.

At Ronnie Scott's club in Birmingham on Thursday night, Feliciano routinely risked the most outrageously difficult runs up and down the fretboard, hammering out long, improvised solos that provided the missing link between Spanish flamenco and Chuck Berry. It's all done at a speed that defies the eye, and with the kind of intensely personalised chord-shapes that would cause any guitar-anoraks hoping to transcribe the blur of fingers into tablature to throw down their pencils in dismay. As with the best Gypsy jazz guitarists in the lineage of Django Reinhardt, the result provokes continual laughs of delight, as reason is comprehensively trashed by the imp of the perverse. What Feliciano does with his guitar is impossible. Yet he does it again and again, taking his left hand so far beyond the bridge of the instrument that he sounds like Harpo Marx.

He also does it as just another part of an act which veers alarmingly from genuine genius to superior pub-entertainer. The chunky middle-aged man sitting on a bar stool strumming his acoustic guitar has the slightly careworn look of a seasoned pro, and his black shades, longish dark hair and black leather waistcoat are like the uniform of a crying-into-his- beer country singer grown old in the service. The four-piece band, while adequate, is hardly inspiring. Feliciano slightly undermines his stunning guitar pyrotechnics and sensitive, original compositions with covers of songs by Eric Clapton, Elton John and Jimi Hendrix that don't really do full justice to his art.

As with Terry Callier, another Sixties singer-songwriter and guitarist whose Latin-tinged compositions have recently been taken up enthusiastically by the latest of jazz-funk clubbers, Feliciano risks becoming successful again at the cost of being misunderstood. He's perhaps nearer to the Sixties folk-jazz tradition of Tim Hardin, Tim Buckley, Richie Havens and Bill Withers (two of whose songs he covered tonight) than he is to funk, however authentically Latin he may be.

The rather hard-edged sound of this performance also served to conceal the more sensitive side of Feliciano's character. Only in the quieter numbers, such as a couple of killer Latin love songs sung in Spanish and an affecting version of Goffin and King's "Will You Love Me Tomorrow", did his voice come across as well as his incredible guitar-playing. The vulnerability one sensed throughout is only fully revealed at the end, when Feliciano leaves his stool and stands a little awkwardly to receive the applause before being led off stage by his minder. "Genius" might be pushing it a bit, but Jose Feliciano is certainly very special. And boy, can he play the guitar.

Jose Feliciano: Jazz Cafe, NW1 (0171 344 0044), Mon-Sat.