Beethoven, Schumann, Franck Renaud Capuçon, violin; Martha Argerich, piano Deutsche Grammophon   Three violin sonatas by great nineteenth century composers, all in A, grace this recording by violinist Renaud Capuçon and pianist Martha Argerich. Longtime collaborators, the duo sound seamless in these performances. They create detailed renditions, faithful to the scores but keen to put their own stamp on the pieces.   The first movement of the Schumann exemplifies this approach, with the performers digging into the main theme and unspinning  legato lines in its development, the tempo treated flexibly. In the second movement, an Allegretto of considerable delicacy, Capuçon