Information on differentia
In the late thirteenth century, a tonary (ff. 209v-212r) was added to this manuscript in diastematic neumes, although the rest of the manuscript is written in adiastematic neumes and dates from the twelfth century. Throughout the manuscript, differentiae are indicated by tonary letters, but these tonary letters are not replicated in the thirteenth-century tonary, and there is no clear indication of how these two systems of differentiae identification correspond with each other. The differentiae included in the Differentiae Database are from the tonary.
Hardeman, Anita. Inventory of Köln (Cologne), Erzbischöfliche Diözesan- und Dombibliothek, 215. Edited by Andrew Mitchell and Debra Lacoste. In: Cantus Manuscript Database for Latin Ecclesiastical Chant: Inventories of Chant Sources. Directed by Debra Lacoste (2011-), Terence Bailey (1997-2010), and Ruth Steiner (1987-1996). Web developer, Jan Kolácek (2011-).
Images: ABreviarum Franconicum, Codices Electronici Ecclesiae Coloniensis (CEEC), Erzbishöfliche Diözesan- und Dombibliothek, Universität zu Köln