Air, Dome, Brighton

If, according to that well-worn cliché, the English are emotionally repressed beings and the French uninhibited and open, then Nicolas Godin and JB Dunckel of Air were clearly born on the wrong side of the Channel. In the privacy of their studios, these middle-class boys from leafy Versailles are capable of making beautiful records that overflow with tenderness, melancholy and warmth. Ask them to play them live, however, and an unexpected frost descends.

Tonight's set draws heavily on Talkie Walkie, a new album on which they return to the wafty melodies and diaphanous textures of their massive-selling 1998 debut, Moon Safari. But so strange is the sound emanating from the stage that for a few minutes I wonder if I've turned up for the wrong show. We should probably be thankful that Dunckel has abandoned the cape he sported on Air's last tour, but, sadly, the penchant for portentous noodling has remained. "Run", a sweet, plinky-plonky number on record, begins in the Hammer House of Horror and ends in a real-life prog nightmare; "Venus" is so unfamiliar, it sounds as though Godin is playing it in the wrong key. The roaring bass that threatens to turn our ribcages into a pile of dust is physically impressive, but it quickly descends into a monotonous dirge.

It's clear that Godin and Dunckel are reluctant performers. On stage, they keep their heads down and exude little in the way of warmth and humanity. They say virtually nothing, ending every song with a clipped, "Thank you", and Godin thinks nothing of playing guitar with his back to the audience.

Occasionally, a moment of melodic beauty breaks through the muddy surface. "Alpha Beta Gaga", with its cheerfully whistled chorus, is terrific, and both the tender, flute-laden "Cherry Blossom Girl" and "Biological", a song in which a lover is reduced to her natural components ("Thousands of hairs, two eyes, only it's you/ Soft skin, billions of genes, again it's you"), bring a lump to the throat. Without the use of the vocoder, Godin and Dunckel's voices have a sad, disembodied quality, as if coming from disconsolate astronauts cast adrift in space. But, alas, such pleasures are rare, and for the most part, one longs to hear the record rather than this leaden imitation.

Songs from their past two albums fare no better. "People in the City" and "Wonder Milky Bitch", from Air's 2001 pseudo-symphonic folly 10,000 Hz Legend, are as baffling as on the day they were released, and it's with discernible testiness that Godin and Dunckel play tacks from Moon Safari, the album that made them rich. "La Femme d'Argent" comes with an insistent and intrusive beat, and "Sexy Boy", performed as an encore number, is played so fast, you can only assume that Godin and Dunckel have somewhere else to be. If so, then they are not the only ones. I can't get away quickly enough.

Touring to 13 March (www.astralwerks.com/air)