The viola established itself as a prominent solo voice in the 20th century, but the three works here illustrate the instrument’s wide spectrum in chamber music of the 19th century. Concluding with a striking series of free variations, Mendelssohn’s Viola Sonata in C minor is notable for its combination of dignified melancholy, exuberance and lightness of texture, culminating in a striking series of free variations. Prague-born Johann Wenzel Kalliwoda’s Six Nocturnes, Op. 186 exemplify the beautifully crafted poetry and lyric features for which he was so admired, while Georges Onslow’s Viola Sonata, arranged from the cello original, is exceptionally elegant and virtuosic.