A Portishead gig is a rare treat indeed. They may seem the ultimate studio band, hardly famed for their eagerness to churn out new material or to trot up and down the country in a transit, but when the trip-hop originators gear up their dark and ominous creation for a live outing it is something that simply has to be witnessed.

Mainly playing material from the black velvet classic new "Portishead" LP, Portishead made a sparse stage their own, turning the large hall of Barrowlands into a smoky nightclub from beyond the grave. After building up such a huge following with "Dummy" (which the abysmal This Life practically gave the Kiss of Death to), "Portishead" saw the band retreat inwards, finding some particularly unsettling and eerie muse in the process. More horror core than Goth, the new material is pre-millennial tension given voice: the sound of a century dying, then rising from the grave.

Whether bathed in deep red light so as to resemble the blood-drenched Carrie at the prom, or wrapped in indistinct blue tones which rendered her almost translucent, Beth Gibbons was the focus of a band producing some of the most shiver-inducing music ever heard. Gripping the microphone with both hands, eyes tightly closed and shoulders hunched like some post-modern Artful Dodger, she let the samples, strings and beats going off around her envelop her, adding her remarkable voice to an already distinctive sound. Soft and unsettlingly warm at times with songs like "Humming", or stained-glass shatteringly piercing and powerful during numbers like "All Mine", Beth's voice is unique, an instrument in its own right. And one that seems to have a black magic all its own, capable of holding you (and several hundred others) spellbound as it does mysterious things to you without your permission.

Highlights of an excellent set were a frighteningly penetrating "Mourning Air", a song teetering on the edge of wind-blasted cliffs and closing its eyes; "Over", with its down at the cemetery at midnight echoing melodrama; and a blinding and blistering "Glory Box", shaken from its "Dummy" torpor and injected with a forbidden serum to make its veins stand out. Throughout, the band appeared to be enjoying itself, Beth in particular losing herself in her own sounds and at other times reaching into the crowd and yelling her thanks to an enslaved but appreciative audience. A trip-out encore of "Elysium" was a suitable climax: strobes pulsing as beats exploded and Beth primal screamed into the microphone before abandoning herself completely and surfing onto the heads of the audience. When they left the stage, the hall was emptier than it had ever been before.

Sell your soul to Portishead - before they take it.