Like his Italian predecessor Giorgio Vasari, Karel van Mander I is best known as an author, in his case of the first collection of biographies of Netherlandish artists, but he was also a highly skilled and wonderfully imaginative draftsman. This drawing depicts a story told in Ovid's Metamorphoses (5.294-678) in which the nine Pierides, daughters of King Pierus of Emathia, are turned into magpies after losing the singing contest to which they challenged the nine Muses. The scene is set at one of the sacred sources on Mount Helicon or Mount Parnassus. Probably following the example of a print after Rosso Fiorentino, van Mander seems to have cast Apollo as the final judge. This drawing and two similar sheets by van Mander at the Uffizi, Florence, may have been meant as the continuation of an elaborate but aborted series of print illustrations of the Metamorphoses by van Mander's great contemporary and friend Hendrick Goltzius. Goltzius in turn must have been incited to work on the series by van Mander's interest in Ovid's book, on which he published a commentary in 1604.