This scholarly work delves into the nuances of medieval music theory, with a focus on the meaning of ligatures in the mensural notation of the 12th century. Drawing on extensive research, the author offers a detailed analysis of historical sources and provides new insights into the development of music in medieval France. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.