Apollo and Pan had a musical contest. Midas chose Pan as the victor, and Apollo punished Midas by giving him ass's ears. Midas stands between Apollo who is seated with his lyre on the right, and Pan with his pipes to the left.The subject derives from Ovid, 'Metamorphoses' (11).
The fresco (transferred to canvas) comes from a series painted in the Stanza di Apollo in the garden pavilion of the Villa Aldobrandini, Frascati.
The artist painted all six figures, but the landscape may have been made by an assistant. Seven chalk preparatory drawings for the figures by Domenichino survive (Windsor, Royal Collection).
From The National Gallery Podcast: Episode Forty Six, August 2010