MULTIMEDIA: Laurie Anderson RFH, SBC, London

So far Laurie Anderson has avoided doing an acoustic album, for obvious reasons (given her dependence on electronic gadgetry, Laurie Anderson Unplugged would have about the same entertainment value as a television unplugged). In Speed of Darkness, however, she gets about as far back to basics as she's ever likely to go. For this latest performance, unveiled on Monday night at the Royal Festival Hall, she has abandoned all the elaborate visual paraphernalia she's known for. Instead, she appears alone in front of a blank black wall, standing among a relatively impoverished collection of electronic gizmos.

The reasons for this soon become clear: the main theme here is technology and its effects on our relationships with each other and with the world outside - opening up new modes of identity, new ways of perceiving, new means of communicating, but also interposing new barriers. In stripping away the technology, Anderson's intention seems to be to demolish barriers. Certainly, the show follows a curve of increasing intimacy between artist and audience.

To begin with, Anderson puts herself on display, playing the violin virtuoso. Then, accompanying herself on keyboard, she addresses the audience directly, reciting poetry and telling elliptical fables. Finally, she just chats, delivering a series of anecdotes on life in the digital age.

It's an impressively controlled, slick performance, and, if nothing else, you have to admire Anderson's stamina - she's on her feet for not far off two hours. But that doesn't make up for the appalling banality of what she has to say. Sometimes she's banal in a solemn way ("I remember all my loves. I remember the way they held me. World without end"); sometimes she's simply obscure (one of her fables begins "Alexander the Great wasn't killed during the battle of Macedon like everybody thinks he was..."). Mostly, she's banal in the same way as a back number of Punch, swiping at the craziness of the modern world: all those newfangled computers and their silly jargon - artists are now known as "content-providers", forsooth! Without the music and the mannered delivery (long pauses between words) she'd be Basil Boothroyd.

There are lighter moments along the way - a questionnaire to discover whether your grandparents come from outer space, which includes such questions as "Did your grandparents work for the benefit of life on this planet?"; a Texan housewife flying for the first time, who thinks she is in space and that the lights of towns below are constellations. But these always go off into pretentiousness ("This is why humanity will survive. We are basically... insane") or cheap metaphor ("I keep getting a message on my screen... it says I'm losing my connection"). In the past, Anderson has been enigmatic, provocative, exciting. But Speed of Darkness embodies its title in unexpected ways: very slow, very dull.