While Zoltan Kocsis is widely regarded as one of the finest pianists of his 1950s generation, in Britain at least his achievements as a conductor are less well appreciated. Kocsis has long pursued parallel careers (three altogether, for he is a composer too). He founded the Budapest Festival Orchestra with Ivan Fischer in 1983, and remained its artistic advisor for 14 years; now he is in charge of the Hungarian National Philharmonic.

As this concert with the City of Birmingham Symphony demonstrated, he generates the same electricity in front of an orchestra as when he is playing the piano. The programme was not exceptional - Ravel's Le Tombeau de Couperin, Bartok's Viola Concerto, Tchaikovsky's Fourth Symphony - but this was by a long way the most involving concert I've heard in Symphony Hall this season; each item had its own separate sense of occasion.

The Ravel was not the usual suite but an expanded and reordered version that included Kocsis's own orchestrations of the two piano movements that Ravel omitted; the Fugue seems slightly ungainly in this guise, but the Toccata is a wonderful tour de force, dashingly reimagined and cunningly paced. It was good to hear the CBSO's virtuosity challenged so effectively too, and its account of Tchaikovsky's Fourth Symphony - equally lean and unsentimental, even though Kocsis cranked up the finale to a ferocious climax - was dispatched with maximum efficiency.

Conductor and orchestra made a better case than most for the viability of Bartok's concerto; if the viola repertory were not so impoverished, the piece would surely have remained as the pile of sketches the composer left at his death. Much of the credit for that should go to the soloist, though: Tabea Zimmermann is the kind of transforming artist who can turn the simplest C major arpeggio into a thing of wonder. Bartok's solo writing is marginally less skeletal than that, though the orchestral textures are basic enough, yet Zimmermann charged it with intensity and real drive whenever she could.