Abstract
In book 7 of his Speculum musicae, the fourteenth-century music theorist Jacobus structures a defense of music as it had been practiced in the thirteenth century by such eminent musicians and theorists as Lambertus, Franco, and Petrus de Cruce against the practices of certain unnamed moderni active at the time of Jacobus’s writing. While Jacobus’s quotations from various theoretical works by Jehan des Murs have long been recognized, it previously had been supposed that the remaining quotations were jumbled references from many different theorists. With specific reference to Philippe de Vitry only two quotations from the text edited in vol. 8, Corpus scriptorum de musica, had been identified previously. In fact, there is substantial sustained treatment of a single author, whom I have termed the doctor modernus and who is not Jehan des Murs, that occupies at least five contiguous central chapters of book 7. Following Jacobus’s practice in the previous six books of commentary on a handful of specific works, the writing of Book 7 appears to have been structured around the written works of just four theorists: Lambert, Franco, Jehan des Murs, and the doctor modernus. Furthermore, Jacobus’s vehemence toward the doctor modernus was particularly pronounced and may indicate a personal relationship between the two men. His treatise is quoted with reference to some fundamental ars nova theories, such as extension of long notes beyond the duplex long, remote imperfection, the use of imperfect longs, and imperfect measure in general, and his treatise is described as outlining the precepts of both the old and new arts. The similarities between the treatise of the doctor modernus and many ars nova theory texts (some of which were attributed to Vitry) hints at the possibility that the treatise of the doctor modernus may have been the ancestor text that these other texts had in common, and hence also that Philippe de Vitry may have been the author of the text known to Jacobus, whose subject was the Ars vetus et nova.
