Arditti Quartet, Purcell Room, London

This concert by that indefatigable 30-year-old outfit the Arditti Quartet was the second event in the three-concert International Benjamin series on the South Bank. It was planned by the even more indefatigable George Benjamin - who, in addition to rehearsing, conducting and playing in the other two concerts, contrived to attend the premiere of his own latest orchestral work in Chicago, all within five days.

This concert by that indefatigable 30-year-old outfit the Arditti Quartet was the second event in the three-concert International Benjamin series on the South Bank. It was planned by the even more indefatigable George Benjamin - who, in addition to rehearsing, conducting and playing in the other two concerts, contrived to attend the premiere of his own latest orchestral work in Chicago, all within five days.

And he was back to hear the Ardittis launch into their opening item, Elliott Carter's String Quartet No 5 (1995). Still composing intensively at 96, Carter has proved most indefatigable of all in coming up with fresh approaches to the standard genres. The Fifth Quartet is a divertimento-like sequence of six contrasting short movements, preceded and linked by seemingly random rehearsal-like passages.

The Ardittis went at the piece with their usual abrasive intensity, making much of the colour contrasts between the remotely glacial fifth movement and the bizarre pizzicato sixth. But they could not efface memories of the humour and refinement the Pacifica Quartet found in the work at the Wigmore Hall last year.

Perhaps more completely successful was the Ardittis' UK premiere reading of the String Quartet (2004) by the German composer Hanspeter Kyburz. This followed a somewhat Carterian cyclical plan, ringing the changes on three types of writing: accompanied solos for each player; passages of vigorous counterpoint; and patches of more unified texture. The surface of the music often fizzed with chirruping atmospherics, but it was underpinned by more stable long-term harmonic processes than in the determinably atonal Carter.

You couldn't really describe Jonathan Harvey as indefatigable, as so many of his works seem to strive for an unworldly state of spiritual bliss. In his 36-minute String Quartet No 4, here receiving its London premiere, all the latest electronic wizardry from Ircam in Paris was deployed to transform and project "psychic metamorphoses" of the quartet's often barely audible bow strokes, tremolo shimmerings and so on, in complex spatial patterns from speakers placed around the auditorium.

Yet, for all the skill, not to say expense, involved, it was difficult to feel that any of this was very new in concept or actual sound. The "flying fantasies" Harvey spoke of in his note came over less as "astral travel" to Nirvana than a trip down the history of electronic music's memory lane.