Anti-Pop Consortium, Mean Fiddler, London

Dark and directionless electronic noodling

It's not every day that you come across a rap group that cite Sun Ra and Sonic Youth as their influences. But Anti-Pop Consortium are hardly your average rap group. This Brooklyn outfit eschew the braggadocio of their hip-hop peers in favour of elaborate rhymes and lofty experimentalism. On record, they peddle a refreshingly original sound – hip hop stripped to its bare bones and reassembled with the help of avant-garde electronica and free-form jazz. Not altogether surprisingly, they have a particularly high-brow following. Those boffs from Radiohead liked them so much that they decided to take them on tour last year.

Anti-Pop Consortium began life as part of New York's poetry underground in the mid-Nineties.They recently signed to the Sheffield-based label Warp, home to electronic experimentalists Autechre and the Aphex Twin. It's an unusual move for a rap act but one that fits perfectly with their ethos of experimentation.

Yet, while they must be praised for trying to broaden the parochial boundaries of hip hop, you wonder if they have lost sight of their original goal – that is, presumably, to inspire and entertain. Things begin promisingly enough. They arrive on stage in a barrage of beats shouting about how they're "gonna light this joint" and "get London jumpin' ", and for a while you believe them.

Beans, High Priest and M Sayyid (they may take an intellectual approach to their art but they're not above giving themselves silly names) are dextrous rappers but their verbal skills aren't enough to sustain the show. Their songs are set against a stark backdrop of electronic twitching – "Ping Pong" starts forcefully enough but tails off with some protracted electronic noodling. As the evening wears on, the pace barely wavers and the instrumentals remain abrasive, dark and directionless.

Matters are made considerably worse by the band's insistence on the lights being turned down. One of the joys of live hip hop is the spectacle of man and microphone but for the duration of tonight's show our hosts are mere silhouettes. With little to focus on either visually or aurally, it's impossible to concentrate.

This is frustrating principally because you know that they are capable of so much better. While their latest Arrythmia record is wilfully experimental, it has a more inclusive feel about it. If the surreal nonsense-verse lyrics don't keep you entertained then there are at least some jaunty rhythms to keep your toes tapping. But these details are lost when played live.

It's a laboured and obstinate performance that keeps the listener at arm's length.