Inside this year's year-end greeting cards is the rubber-stamped word "Sing." It should really read "sung" since the edition's envelopes employ every piece of sheet music that have been stashed in a "Christmas Music" binder, since my teenage, choir-singing years. Cropped pieces of the reproductions in an old book about "Les Tres Riches Heures Du Duc De Berry" (Book of Hours) provide the colour.