Antonio Vivaldi (1678-1741) 
Vivaldi worked in Venice as a priest and director of music at an orphanage for girls, Ospedale della Pietà. 
He composed settings of the Magnificat canticle, a regular part of vesper services. Musicologists 
differ in dating the works, for example before 1717 or in 1719. According to the musicologist Michael Talbot, Vivaldi wrote the earliest version in G minor for the orphanage c. 1715, and copied it for a Cistercian monastery of Osek soon afterwards. He revised it in the 1720s, making the tenor and bass parts more suitable to male voices, and adding two oboes, which he used prominently as obbligato instruments in an expanded version of "Sicut locutus est". This version became known as RV 610. While Vivaldi assigned two choirs, with instructions in the choral movements to use one or the other or both, it remains monochoral music 
Vivaldi wrote a later setting, RV 611, which retained the choral sections but replaced the three sections for solo voices by five more elaborate arias, in which individual girls from the orphanage could show off their skills. Their names were noted in the score. 
This edition is made for SSA soli with an all female setting SSAA of the choir part.