Frank Peter Zimmermann / Heinrich Schiff, Queen Elizabeth Hall, London

Rather surprisingly, the significant repertoire for the duo-medium of violin and cello dates almost entirely from the first three decades of the 20th century and is built round just two undeniable masterpieces. The first of these, Kodaly's vast and demanding Duo, Op 7, appeared in 1914, and Ravel admitted his even more hair-raising Sonata for Violin and Cello (1920-22) was conceived partly - and typically - to outdo the Kodaly in sheer virtuosity.

Not even as distinguished a duo as the violinist Frank Peter Zimmermann and the cellist Heinrich Schiff would lightly consider attempting both pieces in the same concert. So in this Queen Elizabeth Hall appearance, they plumped for the Ravel as grand finale, leading up to it with duos by Martinu, Honegger and Schulhoff, and beginning each half with transcriptions of Bach canons from The Art of Fugue.

And if the players sounded rather choppy in the first of these - the "Canon alla Duodecima" - they soon found their form in Martinu's early Duo No 1 (1927): very much influenced by the Ravel in its bi-tonal Preludium, but taking off in its Rondo finale in manic cadenzas.

Honegger's more substantial three-movement Sonatine (1932) also has touches of Ravel in its more pastoral simplicities - the plaintive reversion to the minor-key opening at the end of the first movement was particularly well brought off in this performance. But the work somehow fails to achieve a focused character of its own.

Nor does the four-movement Duo (1923) of the very gifted Jewish-Czech composer Ervin Schulhoff, who was later to perish tragically in a Nazi concentration camp - though no end of contrasting influences, modernist, populist and folkloristic are brought into lively, colourful collage, on the way to its motoric end.

The Ravel, by contrast, is unmistakable from its very first bar - though this was a new, post-First World War Ravel: linear, acidulated, even violent in its disenchantment. In four movements, running over 20 minutes and stretching its performers to the very limits, it will never be popular, yet it towered over the rest of the programme and continued to obsess this pair of ears long after it was over.

Possibly the opening movement could have been less hastily unfolded, though the arch-shape of the slow third movement was nobly spanned. But the snapping ostinati of the scherzo and drumming, skirling textures of the finale accumulated a terrific impetus and volume as performed here - provoking a comparable response from a sizeable audience. Whereupon Zimmermann and Schiff returned to repeat the "Canon alla Duodecima" by way of encore - this time, with perfect poise.