The richly decorated music pages behind the protective curtains once belonged to a hymnal. This so-called Gradual was produced by hand by the nuns of the Cologne convent of St. Clare.

The careful illumination of the parchment pages was not intended to provide income for the nuns, but was—much like a form of prayer—a meditative practice meant to foster concentration on God. One of the nuns, the abbess Petronella, even had herself depicted on each individual page.

But what was the purpose of the surrounding decorative borders, filled with humans, animals, and hybrid creatures? These imaginative depictions are playful caricatures known as drolleries, which often appear in medieval manuscript illumination and served to provide variety and entertainment.