The Wikipedia article of the day for September 1, 2020 is Vespro della Beata Vergine.
Vespro della Beata Vergine (Vespers for the Blessed Virgin) by Claudio Monteverdi is an extended composition for the evening vespers on Marian feasts, printed in 1610. The composer set the usual Latin psalms and Magnificat, but also solo concertos in the style of the emerging opera. The ambitious composition, which uses traditional Gregorian chant as cantus firmus, is scored for soloists, choirs of up to ten parts, and orchestra. Monteverdi wrote it when he was maestro di capella in Mantua, where he served as musician and composer for the Gonzagas, the Dukes of Mantua. He had it printed in Venice, with a dedication to Pope Paul V dated 1 September 1610 (pages from a copy pictured). He then travelled to Rome to deliver it to Pope Paul in person. Monteverdi became director of music at San Marco in Venice in 1613. His Vespers represent a milestone of music history at the transition from Renaissance to Baroque styles.