In the last decades of the 17th century, the feast of Christmas in Lutheran Germany underwent a major transformation when theologians and local governments waged an early modern "war on Christmas," discouraging riotous pageants and carnivalesque rituals in favor of more personal and internalized expressions of piety. Christmas rituals, such as the "Heilig Christ" plays and the rocking of the child (Kindelwiegen) were abolished, and Christian devotion focused increasingly on the metaphor of a birth of Christ in the human heart. John Sebastian Bach's Christmas Oratorio,...