The Renaissance Reform of Medieval Music Theory: Guido of Arezzo between Myth and History (review)

Guido of Arezzo is surely the most familiar of all Medieval music theorists; certainly no history of music course fails to introduce Guido as the inventor of the staff and of solmization. And many, if not most, also credit him with the system of overlapping hexachords, taken as the way musicians of the later Middle Ages and the Renaissance conceived pitch relationships, and therefore seen as the key to understanding medieval and Renaissance music properly. It will therefore come as a revelation to a great many—perhaps even to some specialists in the area—to learn the degree to which the Guidonian theory we all met as undergraduates is in reality the product of reworkings, reconceptualizations, "reforms," and other manipulations by later writers.

In this rich but compact book, Megozzi retraces the course of Guido's legacy from the eleventh century to the end of the sixteenth, with an epilogue covering the period up to the early nineteenth century and the establishment of musicology as a scholarly discipline. The book is, of course, a contribution to the history of music theory, but—unusually for music theory—it also partakes of reception history, engaging wider intellectual history at key points. This monograph thus belongs to that narrowest of subspecialties: the metahistory of music theory; but, precisely because it occupies a nexus among several disciplines, it will be of interest to scholars working in a variety of niches: medievalists, Renaissance scholars, performers of medieval and Renaissance music (to name the obvious), not to mention those engaged in the teaching of music history at all levels.

The wide scope of the book (almost six centuries, plus extensions, of music history), features a large cast of characters, with an interesting variety of motives and agendas. Running through all this, almost as an idée fixe, is the hexachord system itself, as a pedagogical tool, and as a fundamental theory of pitch space. The book is, appropriately, organized into two principal sections, each with four chapters. Part 1, "Guidonian Solmization in Music Theory and Practice," covers the history and development of Guido's ideas to the end of the trecento, reading the primary sources "as 'informants' on the basic questions of the nature and function(s) of Guido's hexachord as understood in the Middle Ages" (p. 13). Part 2, "Reforming the Music Curriculum in the Age of Humanism," continues the story to the end of the sixteenth century, "address[ing] the historiographic side of the question . . . to understand the historical circumstances that led to the emergence of the foundational view of the hexachordal system" (p. 13). These are framed by an introduction and an epilogue, and punctuated by an "Interlude" with the intriguing title "All Hexachords are 'Soft.'"

Mengozzi opens the introduction with a series of questions, the first of which is, "Was there a hexachordal season in the long history of Western music?" That is, he continues, was there a time when "the octave scale . . . did not possess the cognitive and normative weight that it undoubtedly has had since the Enlightenment?" (p. 1). The introduction unfolds an overview of the spread of the hexachord system, and the friction between it and the system of seven pitch letters—the essential basis of the story to be told. Of central importance is the medieval distinction between proprietas (the six-note segment of the gamut) and deductio (the attached set of syllables). As Mengozzi sums it up, "this monograph aims to chart out the rich and convoluted history of the hexachordal system as a way of appreciating the cultural factors that transformed that system from a low-key method for sight-singing into an all-around structural pillar of early music" (p. 15).

Chapter 1, "Guido's Musical Syllables: Conflicting Views from Modern Historiography," further explores the differences of opinion among modern musicologists (citing a large number of them) concerning the...