4 The manuscript is described by Huglo, Michel and Phillips, Nancy in The Theory of Music: Descriptive Catalogue of Manuscripts, ed. van Waesberghe, Joseph Smits, Fischer, Peter and Maas, Christian, RISM, B/4 (Munich, 1992), 74–8Google Scholar; and by Pesce, Dolores, Guido d'Arezzo's Regule Rithmice, Prologus in Antiphonarium and Epistola ad Michahelem. A Critical Text and Translation (Ottawa, 1999), 112–14Google Scholar. See also Mews, et al., ‘Guy of St Denis’ and ‘Introduction’ in de Grocheio, Johannes, Ars musice, ed. Mews, Constant J., Crossley, John N., Williams, Carol, Jeffreys, Catherine and McKinnon, Leigh, TEAMS (Kalamazoo, MI, 2011), 12–14Google Scholar.