Abstract

The ninth-century treatises Musica and Scolica Enchiriadis are the first musical writings in the West to present a theory of organum, a mode of plainchant performance that is the earliest known form of Western medieval polyphony. The fundamental principle of this theory is that the intervallic relationship between the simultaneous melodic lines be one of "consonance" . Nevertheless, intervals arise between the voice-parts that are not symphoniae; the theory responds to this, not by explicitly invoking the concept of dissonance, but by excluding these non-symphonic or non-consonant intervals from the concept of "organum." Through close analysis of the relevant texts, the dissertation seeks to explicate this concept of organum as symphonia in terms of a "metaphysics of consonance" that the Enchiriadis theorists took over from the most influential of the musical writings of late Antiquity, the De institutione musica of Boethius. ;The metaphysics of consonance projected therein is a particular development of the Pythagorean-Platonic conception of music, in which the symphoniae, because of their simple numerical ratios, represent the universal, divinely ordained rational principles of cosmic order and harmony. After a section devoted to showing that such "speculative" ideas about music formed the basis of the "practical" theory of the Enchiriadis treatises, the dissertation goes on in Part II to find that the relationship between consonance and dissonance in the Boethius Musica is structured as an unequal, hierarchized opposition, in which consonance holds the dominant position in particular because of its virtual identification with the metaphysical ideal of unity. Conversely dissonance, the opposed term of the hierarchy, represents the negative values of duality and difference, and hence discord, conflict, and disorder. Consequently, through various textual strategies, consonance is identified with "music" itself, while dissonance is effectively excluded from that domain. ;The concept of organum in the Enchiriadis treatises is found to be determined by this same metaphysics of consonance, with its consequent tendency to exclude or marginalize dissonance, a conceptual pattern that has resonated throughout the subsequent history of polyphonic theory and practice in the West