Mendelssohn Viola Sonata in c-minor (1824) Felix Mendelssohn's Viola Sonata in C minor was composed when he was only 15 years old. The autograph score is dated 14 February 1824. The work was not published in Mendelssohn's lifetime- in fact until 1966[1] - and it was not assigned an opus number. Mendelssohn himself was an accomplished violinist and violist, playing one of the viola parts in a..