Arditti Quartet, Wigmore Hall

James Clarke's Second String Quartet (2009) was thrillingly, almost treasonably, un-British. It began by summoning up a high-pitched, dust-stormy sound as if the Ardittis were a crowd of Palestinian zaghareet-ers. Beefy trills, open strings, scrubbed pitches, squirty figures that sounded as if they'd come from tubes of toothpaste, were all heaped on top of each other to create a messy sandwich of ululating noise. An attempt was made to untangle the web of sound. Silence followed failure. And with this the opening caterwauling returned. Again and again the cacophony tried and failed to find a conclusion. It was as if the Ardittis were trying to find their way out of a maze - or a nightmare.

One escape appeared to take place under the cover of night, with a crepuscular development that was fast and strange. Another journey saw the first and second violin (Irvine Arditti and Ashot Sarkissjan) engage in civil war. Many attempts faltered at a nowhere point. Somewhere along the line a consonance broke out, so profoundly startingly a moment I was convinced it was coming from beyond the hall. At the same time a scrubbing figure - like TV snow - muscled its way into things and attempted to consume the work and our ears. But yet again the din was de-composed.

What a joy it was to see a British composer playing around with visceral and conceptual worlds in the manner of the big boys in Europe. The audience gave Clarke a hero's welcome.

Brian Ferneyhough's exile has been even more prolonged. His programme notes suggested that he might even have forgotten his mother tongue. "This multiplicity largely undermines the spirit of the original autonomous 'time slice' principle, leading to a sort of mirrored or negative hierarchy of material and form conveying a qualitative reformulation of the work's initial conceptual environment." Eh?

So, a homecoming has been long overdue. Yet if his Sixth String Quartet (2010) was sent as a means of buttering the London audience up in advance of the Barbican day dedicated to his work on 26 February, it wasn't doing it for me.

I've never been convinced by the New Complexity tag that Ferneyhough has acquired. I came with open ears. I read and listened. I listened and read. Yet I came away from this performance defeated. Bafflement refused to give way to any enlightenment. I could make neither head nor tail of Ferneyhough's 20-minute work. I tried following the tiny fragments and their fleetingly intriguing textural journeys. At times the work seemed to be making sense as a mini-Mahlerian canvas full of intense collisions and sharp changes of tack. But it was all in vain. I was flummoxed in the face of what seemed like a starry sky of discombobulating chaos.

The two composers showcasing world premieres in the second half were mirror images of Clarke and Ferneyhough: foreigners in exile in Britain and, on the evidence last night, champions of mellower British musical idioms too. Their programme notes were also telling. While the Brits hid behind academic obfuscation - Clarke refusing to provide a verbal accompaniment and Ferneyhough descending into jargon and gibberish ("adequation" and "emplacement" on top of the above) - the foreigners embraced a policy of full verbal disclosure.

Fujikura's Flare (2010) began a bit like Clarke's string quartet, with an unhinged wildness. But it was a wildness with a breeze blowing through it. None of the threat or humidity of Clarke's start made itself felt. The textural shifts seemed scholarly rather than organic. At one point a dance ambles in softly. Ligeti wrestles with Stravinsky. The feeling is amiable and intelligible but not consistently compelling. In the Clarke and Ferneyhough, the Arditti Quartet became the crucible for musical experimentation. In the Fujikura, the outfit seemed to be being used as a slide show.

There was a pictorial side to Hilda Paredes's world premiere, too. Her stunning three songs for string quartet and countertenor, Canciones lunaticas (2009), pay tribute to the powers of the moon. Pierrot Lunaire is the obvious template but it doesn't overwhelm her vision. The quality of the poetry from Pedro Serrano, the composition and the singing make sure of this. The first song is still and bare. For the singer, it must be like walking through the dark. The confident and vocally mature young countertenor Jake Arditti, however, navigated the lonely terrain with total conviction, never once tripping over the Ardittis' atmospheric undercurrents or the sibilants and whispering.

With a lurch into madness we moved into a faster and punchier movement that the Ardittis invested with their characteristic intensity. There was a hint of early Birtwistle in the directness and fury of the string writing. But the anger evaporates in a cord of springy ricochets as the third song imagines a moon set free from its daily drill. This was a terrific performance of a brilliantly crafted new work, capping yet another fascinating concert from the indefatigable Ardittis.

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