Oh, those crazy ancient Greeks

The Who's Who in Myth and Legend was telling me the story of Io, who caught the attention of Zeus and was then transformed by him into a cow to conceal her from Hera (or alternatively was turned into a cow as punishment by Hera who was in an Olympian snit), somehow then ending up being guarded by Argos the hundred-eyed giant acting under Hera's orders, whereupon Zeus sent his son Hermes to deal with Argos and free Io, which Hermes did by lulling the giant to sleep by playing soothing music on a shepherd's pie.

Pipe. Shepherd's pipe, or syrinx. These myths are making me hungry.