Legend has it that composer Antonio Vivaldi was born during an earthquake. For an Italian, he was also remarkable in that he possessed a head of flaming red hair. This rock star of the baroque era, known as the “Red Priest,” enjoyed enormous popularity. One tourist pamphlet from that time listed him as “one of the great things to see while in Venice.”

Yet history sometimes takes unexplainable and mysterious turns. After Vivaldi’s death, his exquisite music—almost 800 works of incomparable beauty—vanished into the mist.

Nearly 200 years later, in the autumn of 1926, music professor Alberto Gentili was sent to the Salesian College of San Carlo in Turin to evaluate a collection of music. In a basement vault, Gentili was presented with an enormous library of little-known musical texts. There, the professor discovered 14 volumes of dust-covered compositions bearing the name of Antonio Vivaldi.

The Red Priest was reborn...