Nash Ensemble, Wigmore Hall, London

Less well informed media folk may think it smart to assert that "classical music is dead", but this could hardly be more wrong as far as the Nash Ensemble and its following are concerned. Three days after giving an exhilarating concerts of contemporary premieres in the Purcell Room, here the Ensemble was back in the Wigmore, rounding off its 40th anniversary season with a programme of core classics to a packed house.

This was also the first concert to be recorded live for the Wigmore Hall's own CD label. And, while this wonderful line-up of still-young players is well used to studio conditions, one did wonder if the presence of microphones in the hall itself had not induced a certain, untypical self-consciousness, at least at the start.

Was there a tendency to over-articulate the figures and pauses of the opening movement of Beethoven's cheerful early Clarinet Trio in B flat Op 11; a certain exaggerated neatness to Paul Watkins's phrasing of the cello melody that opens its second? By the finale variations, at least, the pianist Ian Brown, the clarinettist Richard Hosford and Watkins were playing with their usual freedom - that special feeling of knowing the notes so well as almost to be conjuring them out of the air.

Whereupon the violinist Marianne Thorson appeared to lead a vivacious account of Mozart's great String Quintet in C major K515. Here, a nice ebb and flow of tempi was secured between the scudding opening material and more relaxed passages of the first movement; Thorson carried on an exquisitely amorous duet with first viola Lawrence Power in the Andante, and the finale went off like a rocket.

The second half reverberated to the youthful sweep and surpassing textural richness of Mendelssohn's Octet in E flat major Op 20 - that unprecedented outpouring of 16-year-old genius - with such distinguished players as Philip Dukes brought in as second viola and Timothy Hugh as second cello. Here, caution was thrown to the winds; the precipitate opening texture could well have run away with itself but for well-judged touches on the breaks. The chromatic turns and radiant risings of the Andante were feelingly negotiated, while the climax of the scrambling finale was almost incandescent in its drive.

Maybe the odd imprecision of ensemble would have been retaken in a studio situation, maybe a noisy page-turn in the finale will prove difficult to edit out - but these should hardly matter given the life-force of this reading. At the end, the audience responded so enthusiastically that Watkins finally had to tell everyone to go home.