Concerto in B-flat for Mandolin and Violin, RV 548
Vivaldi’s Concerto in B-flat, RV 548, shows the innovations he made to the genre. What marked the Vivaldi concerto was not so much the three-movement form — older composers had used it — but the ritornello, a device imported from the opera aria, in the outer movements. The ritornello was an introductory paragraph that set out the main theme, and then returned, often in different keys, as a structural pillar holding the movement together. Another Vivaldi trademark is having the orchestra drop out of the slow movement, leaving it to the soloists and continuo.