At the recent 2015 International Medieval Congress in Kalamazoo, Michigan, I had a chance to present some of my new work on Jehan des Murs, astronomer and music theorist, that I’m working on as a chapter of my monograph Greedy for New Things: Novelty in Music c. 1300-1340. Serendipitously, I presented my paper on May 14. On the afternoon of that exact date 632 years ago, Jehan observed a solar eclipse in the presence of Jeanne de France, the twenty-one-year-old Queen of Navarre – I opened my paper with a description of this event. They observed the eclipse in a castle that Jeanne had commissioned to be built in Saint-Germain, Évreux, but reportedly had named ‘Navarre’ (this name might give musicologists pause, given that minims were supposedly ‘invented’ in Navarre!).
In my paper I addressed the chronology of Jehan’s writings on music theory in light of revised chronologies of his astronomical and astrological works, and I also considered two aspects of Jehan’s scientific orientation that contextualise his work in music theory-namely, how he negotiates the novelty of his work with respect to that of prior authorities (his auctoritates), and his propensity for continuously revising and recasting his writings in order to cater for particular audiences. An abstract of the paper follows, and stay tuned for more in my forthcoming book!
Although he wrote at least two and possibly four substantial music treatises in the 1320s, Jehan des Murs’s primary preoccupation at the beginning of his career appears to have been with figuring out and disseminating within Paris a new system of astronomy devised in the court of Alfonso X in Toledo. Recent scholarship on Jehan’s writings on astronomy offers a more accurate chronology of his output and activity than was the case in 1970 when Ulrich Michels published on the music treatises. We now have a greater understanding of Jehan’s central role in the introduction and development of Alfonsine astronomony in Western Europe—a system that was to hold say until the revolution of the Copernican heliocentric model. This paper reconciles the facts we know of Jehan’s biography with these new assessments of Jehan’s activity as an astronomer in the 1320s. Jehan’s tables of the stars’ and planets’ positions, based upon the experiential data gathered from his own observations made using the latest technologies, along with the new methods he devised for allowing others to easily calculate planetary longitudes, finally offered the possibility of a more precise and accurate calendar. And although Jehan nominally acknowledges his debt to older scholars (in much the same way as he does in Notitia artis musicae), he is more concerned with recording the true positions of the celestial bodies and precisely measuring reality than he is in ‘standing on the shoulders’ of those who have gone before. His writing betrays a confidence (and some might say arrogance) about the veracity and importance of his work and his conclusions. This paper contends that a similar attitude pervaded Jehan’s work as a music theorist where the aim is to more precisely measure, and indeed reform the entire system of musical time with one more clearly based upon the physical reality of sound and time as a sensibly perceived, and a lack of concern with appeasing those invested in older, less accurate, systems.