Sinfonia Concertante, K. 364 (320d) was written by W.A. Mozart (1756-1791) in 1779 while he was on a tour of Europe that included Mannheim and Paris. A sort of hybrid between a symphony and a concerto, it can be considered among the most successful such cross-over works. Instrumentation: 0.2.0.0: 22.214.171.124: Str(4-4-2/2-3-3 in set): Solo Violin. Solo Viola.