When next your church gets heated over the issue of Anglican Chant vs said, BCP vs modern liturgy, guitars vs organs, drums vs no drums, choirs vs pop music bands, call to mind this event from Symeon of Durham’s Historia Regum (ca. 1129; the event is for 1083):
An infamous dissension took place between the monks and Turstin their abbot, at Glastonbury, a man unworthy to be spoken of, whom king William [the Conqueror] had unwisely preferred from the monastery of Caen to be abbot of that place. Amongst other deeds of folly he disdained the Gregorian chant, and began to force the monks to discontinue it, and to learn and sing the chant of one William of Fescamp. As they bore this very ill — for they had now grown old both in that and other ecclesiastical service according to the custom of the Roman church — one day he suddenly rushed upon them unawares into the chapter with an armed military force, and pursued the monks as they were flying in extreme terror into the church, as far as the high altar, while the soldiers pierced the crucifixes, and images, and shrines of the saints, with their javelins and arrows, and thrusting through with a pike one of the monks, even while he was embracing the holy altar, they slew him; and they murdered another at the base of the altar, pierced with arrows. The rest, urged by necessity, bravely defending themselves with the benches and candlesticks of the church, although severely wounded, drove back all the soldiers out of the choir. And then it happened that two of the monks were killed and fourteen wounded, as were also some of the soldiers. An action being brought on this account, as it was evident that the abbot was chiefly to blame, the king removed the same abbot, and placed him in a monastery of his own in Normandy. Very many of the monks were dispersed in prisons through the bishoprics and abbeys by order of the king. (Ch. 167 in Arnold’s edition, trans. J. Stevenson)
Note: William of Fécamp is also known as William of Volpiano. He was abbot of Fécamp from 1001 to his death in 1031. He revised the notation and singing of the monastic office in a number of Burgundian monasteries. Here is an image from an antiphonary believed to have been his, the Antiphonary of St. Benigne, now Montpellier, Bibliothèque interuniversitaire de Médecine, Ms. H159. The image is from folio 25v.