Around the middle of a career lasting over forty years, Guillaume de Machaut (c.1300-77) was afforded an outstanding opportunity to present his oeuvre in a book. The occasion arose in the late 1340s, when a special manuscript was commissioned, perhaps by Queen Jeanne de Bourgogne, for the first time collecting all of Machaut's works, including narrative poems, lyrical poems, musical settings of lyrics, and motets. The manuscript would celebrate Bonne of Luxembourg, the wife of a future king of France. Only the royal treasury could have funded the extraordinary team of craftsmen involved in its production - from the careful preparation of fine parchment, to the calligraphy and ornament of the text, to the carefully copied innovative ars nova musical notation, to the miniatures painted in a shop directed by one of the greatest illuminators in France. Then Bonne died of the Black Death in 1349, just before the manuscript was completed. It would be finished for her son, the future King Charles the Wise. Although Machaut would go on to supervise other manuscripts, none were so luxuriously executed as his first complete-works manuscript (Paris, Bibliotheque nationale de France, fr. 1586), known today as Machaut MS C. The present volume, the first dedicated entirely to MS C, offers a multidisciplinary collection of essays written by fourteen leading scholars, who provide innovative approaches to literary, musical, art-historical, and manuscript studies. It is replete with images, including over sixty colour reproductions from MS C itself.