Chiaretta and Maddalena are as different as night and day. They were abandoned at birth outside the steps of the Ospedale della Pieta, Venice's world-famous foundling hospital and musical academy. Rebellious Chiaretta develops into a dazzling singer, soon becoming a celebrated soloist. Her more reserved sister takes up the violin and forms a dangerous bond with her instructor, the controversial red-haired priest - and suspected womaniser - Antonio Vivaldi. Based on rich historical research this is a fictionalised account of the lives of two sisters.