The nymph Syrinx was fleeing the amorous pursuit of Pan when she found her escape blocked by a river. She prayed to the gods to be saved and was transformed into a stand of reeds. In 1661 Castiglione sent a sketch of Pan and Syrinx to the Duke of Mantua for approval before beginning work on a canvas; this drawing may be related to that commission, though the fluid handling would place it a few years earlier than 1661.