He was, at one time, known as "il Prete Rosso," or "the Red Priest" because; 1) he was a priest and 2) he had red hair. From his bio:
At the age of 25, Antonio Vivaldi was named master of violin at the Ospedale della Pietà (Devout Hospital of Mercy) in Venice. He composed most of his major works in this position over three decades. The Ospedale was an institution where orphans received instruction -- the boys in trades and the girls in music. The most talented musicians joined an orchestra that played Vivaldi's compositions, including religious choral music. Under Vivaldi's leadership, the orchestra gained international attention. In 1716, he was promoted to music director.Here's one of his most famous pieces (chosen out of respect to the calendar):
An incomparably warm and joyful piece played by the equally incomparable Anne-Sophie-Mutter.