Painting in Italian Choir Books, 1300–1500 – The Metropolitan Museum of Art https://www.metmuseum.org/essays/painting-in-italian-choir-books-1300-1500
Unlike books of hours, which were intended for individual devotion and usually small enough to be held in the hand, choir books were created for shared, communal worship and consequently necessitated a larger format.
who sing open-mouthed as they enter the church in the background, the procession winds
