The Allegri String Quartet, the UK's oldest chamber ensemble, is 60 this season, an anniversary celebrated with a Wigmore concert, for the most part finely executed. Successive generations of players have come and gone over the years. The current lineup, none of whom were born when the quartet was founded, is comparatively young. But the group's ethos, stated in the programme, that emotional truth in performance should outweigh flawless perfection of sound, still holds true.

The first half of the concert juxtaposed Beethoven's String Quartet No 5 in A with Shostakovich's No 11 in F Minor, both leader-driven works that allowed the focus to fall on the Allegris' first violinist Ofer Falk. The Beethoven, in which lyricism and closely woven counterpoint jostle for prominence, drew a performance of grand gestures from Falk and clean playing elsewhere, but took a while to find its focus. The Shostakovich, isolating the leader from the other three musicians, was all bleached tones and understated drama, immaculately judged in its clear intensity.

The second half opened with the world premiere of the recently unearthed Quartett-Satz in A (1879) by Ludwig Thuille (1861-1907), a close friend of Richard Strauss and a chamber composer of some stature. We owe his rediscovery in part to the Allegris' advocacy of his work and to Falk's painstaking research in Austro-German archives. The fastidious structure within which Thuille presents his elegant chromatic themes reminds us of his closeness to Brahms rather than to Strauss and the post-Wagnerians. It was Brahms's own String Quintet No 2 in G, with Norbert Blume as guest violist, that brought the evening to its close. The end was a bit of a scramble with some moments of harsh tone. The rest of it was rich, beguiling and very heart-on-sleeve.