Over the following thirty years he composed most of his main works while working there. Vivaldi was only 25 when he started working at the orphanage.

In September 1703, Vivaldi became maestro di violino (master of violin) at an orphanage called the Pio Ospedale della Pietà (Devout Hospital of Mercy) in Venice. He persisted dedicated to Catholicism, to the point that by old age, Ernst Ludwig Gerber considered him extraordinarily bigoted. Vivaldi said Mass as a priest only a few times, and seemed to have reserved from liturgical duties, however he properly continued a member of the priesthood. Not long after his ordination, in 1704, he was given an indulgence from commemorating Mass due to his harsh health. In 1693, at the age of fifteen, he began studying to become a priest. He was ordained in 1703, at age 25, and was soon nicknamed il Prete Rosso, “The Red Priest”, referring to the bright color of his hair, a family trait. One of his symptoms, “tightness of the chest”, has been deduced as a type of asthma. This did not stop him from learning to play the violin, composing, or taking part in musical activities, although it did stop him from playing wind instruments.

Vivaldi biography