Announced as the "king of trance blues", Otis Taylor wields a banjo with regal flair for the opening number, Feel Like Lightning. His latest album, Below the Fold, sets out the subject matter clearly: racial injustice; love gone wrong; childhood memories; misery and the blues. His music doesn't follow the cyclical patterns of the standard 12-bar model, he sticks to a one chord or riff, or a see-sawing two-chord pattern over which he declaims simple lyrics of rage and complaint. Using only two guitars, bass guitar, cello and a few echo units, his band can sustain one mood for a long time, hence the "certified trance blues" guarantee stamped on his CD covers.

The musicians take the stage at the end of a long, late-running evening in the Spitz Festival of Blues, and never look comfortable. They share the stage with a mysteriously assembled drum kit and take long breaks between numbers to tune their instruments. The sound mix is uncomfortable, too, with the bass parts (played by Taylor's daughter, Cassie) inflexible and overly loud, while the cello is inaudible.

They break out of the trance straitjacket for a moment to perform an echo-laden version of Hey Joe. It's a welcome change, but too dull to achieve this great song's customary intensity. Most numbers pump away forever like Velvet Underground out-takes. Taylor is aiming at a singular and uncliched approach to the blues tradition, but the monotonous "trance" formula has neither grace nor energy. Maybe it's an off night, but you don't feel Taylor has mastered the raw ingredients of his sound. Or maybe he's too controlling, never permitting his band to set the songs aflame.

· The Spitz Festival of Blues continues until April 29. Box office: 020-7392 9032