Razumovsky Ensemble, Wigmore Hall, London

Michael Haydn, younger brother of Joseph, was in a fix. Ordered by his employer, the Prince-Archbishop of Salzburg, to compose six duos for violin and viola, he had fallen ill after completing four. Mozart offered to run him off a final couple, to pass off as his own. No one now remembers the Michael Haydn duos, but the Mozart pair remain lasting masterpieces of the genre.

And the endlessly ingenious two-part textures of the longer of them, the Duo in B flat K 424, as delivered by the perfectly matched Norwegian pairing of Henning Kraggerud, violin, and Lars Anders Tomter, viola, were enough to fill the spaces of the Wigmore Hall to brimming. Not a nuance was missed in their warmly spacious unfolding of the slow movement, while the concluding variations worked up a tremendous vivacity and pace.

In fact, Kraggerud and Tomter had been specially brought together for this concert by the Russian cellist Oleg Kogan, under the collective umbrella of his Razumovsky Ensemble. When Kogan himself joined them in the Serenade in C for String Trio, Op 10 by Erno Dohnanyi, the gutsy warmth and power of the sound was almost overwhelming.

Although greatly respected by his Hungarian contemporaries, Bartok and Kodaly, Dohnanyi took little from folk music – a few rustic dronings in the opening and closing March, aside. Rather, his style derived from Brahms, but a Brahms charmingly slanted and coloured, as in the elegantly sinuous melody of the Adagio second movement with pizzicato accompaniment, exquisitely phrased by Tomter. Composed in 1902, this attractive, warm-blooded work must have done much to restore the string trio genre to favour.

After the resinous gusto of their Dohnanyi, these three players surprised us again by sidling into Mozart's great Divertimento for String Trio in E flat major, K 564, with the most veiled restraint, only gradually gaining fullness of tone, and withholding the fullest impact for the climax of the fourth movement variations; while in the second slow movement, Kogan revealed a singing upper register to rival the resonance of Tomter's viola. Yet there was affectionate humour here, too, in the minuets and the effortlessly spinning finale, which brought this singularly satisfying concert to its insouciant conclusion.