Theoretical writings about rhythmic measure in polyphony that date from the thirteenth century are pivotal to establishing a history of music during this formative era. Temporal measure, polyphonic composition, and a system of written symbols by which to transmit a musical work form a matrix that is the basis of music in the Western tradition. It was during the thirteenth century that these elements came together in such a way as to establish a concept of music that differed significantly from any preceding.
The primary locus for development of theories of rhythmic measure was Paris, and the practice may have arisen from the liturgy for the Cathedral of Notre Dame during the last two decades of the twelfth century. A historical shift occurred during the 1270s when the theory of measure in music was taken up by the university community, which brought to bear upon it concepts and methods derived from other disciplines of the liberal arts, primarily logic, geometry, grammar, and rhetoric. This change is manifest in definitions given to fundamental precepts, organization of treatises, intrusion of a more refined vocabulary, and, in certain treatises, an incursion of learned, literary references. In contrast, the theoretical writings dealing with measure in music before the 1270s emerge as a fragmentary surface of what may have been primarily an oral teaching tradition.
The focus of this dissertation has been on close paleographic and codicological examination of individual primary sources using principles of textual criticism for comparison, identifying the nature and purpose of the transmission of these texts, and codicological examination of individual primary sources using principles of textual criticism for comparison, identifying the nature and purpose of the transmission of these texts, and exploration of the context of these treatises leading to a consideration of the broader range of the intellectual history of the thirteenth century. I have sought to define the fundamental differences between a medieval text and the modern concept of text, the codicological and internal characteristics that identify a text as one belonging to a university environment or a monastic tradition, the properties and traits that identify the nature of discourse as didactic, speculative, prescriptive, or descriptive, and the elements that mark a text as essentially secondary and receptive or as original and authoritative.