Tribute To Robert Simpson | Wigmore Hall, London

The last three concerts in the Wigmore Hall's far-sighted Tribute to Robert Simpson, with enlightened sponsorship from the Bluff Field Charitable Trust, have been invigorating stuff. Simpson, who died in November 1997, left behind him the most consistently impressive string quartets (15 of them) by any British composer, a series worth to stand alongside the other great 20th-century quartet-cycles, those of Bartók, Shostakovich and Holmboe. Hearing Simpson in older company - Haydn, Beethoven and Brahms - drove home a bolder conclusion: that he is a master of world standing, a major figure in the history of music.

The Chilingirian Quartet's association with Simpson goes back to their early days - he produced some of their first recordings - and the second cellist in their performance of the Second String Quintet was Steven Orton, another musician who enjoyed the composer's trust. The Second Quintet is the work on which Simpson was working when, in 1991, he suffered the stroke that ultimately killed him; he finished it only with intense effort. It's in a single movement, four calm moderato passages merging into, emerging from, three energetic allegros, almost as if two different pieces were proceeding simultaneously.

The "Chillies" caught its grim, unflinching passion perfectly. By the time he had finished it, Simpson knew he would not be able to compose again, but there's not a trace of self-pity in these taut textures; instead, they are animated by the life-affirming glow at the heart of all his music.

Simpson understood Beethoven's music more deeply than any other commentator I have read. But his deepest insights weren't intended for reading: his own Fourth, Fifth and Sixth Quartets constitute a study of Beethoven's three Rasumovskys, Op. 59, with a profound difference - Simpson cast creative light on Beethoven's processes by mirroring them in his own music. You don't need to know anything of that to appreciate the buoyant invention of these "musical analogies", and the Vellinger Quartet's reading of Simpson's grimly good-humoured Sixth was powered with a fierce energy that would have delighted its creator.

But the garlands must go to the Vertavo Quartet, an all-female ensemble from Norway. They threw themselves at the Bartók Fourth Quartet, taking its ferocious difficulties in their stride with a raw, primal force that immediately raised the hairs on the neck. The hall was crisp with expectation by the time they returned for Simpson's Seventh, a slow-fast-slow arch-shape, its central outburst welling out of the contemplation of vast forces. The Vertavos gave it the most sheerly passionate performance of any Simpson work I have heard: it was nothing less than thrilling.