Johannes de Muris (EN)

Johannes de Muris, Jehan des Murs, 1st half 14th c., French astronomer, mathematician, and music theorist. He was born in the Diocese Lisieux in Normandy, as he mentioned in his first astronomical treatise, De introitu solis in arietem (1318). Johannes de Muris’ date of birth is estimated to be around 1295. He studied in Paris, obtaining his bachelor’s degree in 1318 and his master’s degree between 1319 and 1321. In March 1318, he stayed in Evreux in Normandy, and in 1321 in Bernay, where he observed a solar eclipse. Until 1325, he stayed mainly in Paris and worked at the Collège de Sorbonne. In March 1326 and August 1327, he stayed at the Fontevrault monastery, where he carried out astronomical observations on behalf of Alienor, the prioress. On 29 November 1329, he received a benefice from Pope John XXII in the territory of the Le Bec-Hellouin abbey in the Diocese of Rouen. In 1332 and 1333, he stayed in Evreux. In 1336–37, he presumably returned to the Collège de Sorbonne. In 1338–42, he may have stayed at the court of Philippe d’Evreux, King of Navarre, recorded as “Jehan de Muris”. In 1342, he was one of six canons of the collegiate church in Mezières-en Brenne. In 1344, he was summoned by Pope Clement VI to Avignon, together with another eminent astronomer, Firmin de Bellavalle, to participate in a conference on calendar reform. The two scholars presented their joint work, Libellus de correctione numeri aurei (1346–47), to the Pope on the fifth anniversary of his pontificate. Johannes de Muris remained on friendly terms with Philippe de Vitry, who was a reader of his musical treatises, including Notitia artis musicae and Musica speculativa. A letter to Philippe de Vitry, addressed “ad Philippum de Vitriaco Episcopum Meldensem”, is the last known writing by Johannes de Muris, and the year 1351, when the letter was probably written (Philippe de Vitry became bishop of Meaux on 3 January 1351), is the last known date in his biography. 

During his lifetime, Johannes de Muris gained great recognition as an astronomer and astrologer. Three of his astrological predictions are well known. The first concerns the alignment of planets in 1345. The next two, addressed to Pope Clement VI, refer to political events: one contains a warning against war between the superpowers in July 1357, the other – advice to proclaim a crusade in 1365. Astronomical issues dominate his scholarly work. Of the 27 treatises attributed to Johannes de Muris, more than half concern astronomy, and only five are musical treatises; the rest are devoted to geometry and arithmetic, including Arithmetica speculativa (1324?), based on Boethius’ De institutione arithmetica, and Johannes de Muris’ most famous mathematical work, Opus quadripartitum numerorum (4 books, 1344).  One of the six treatises in the last book of this work, entitled De sonis musicis, has been lost. 

Johannes de Muris’ earliest musical treatise was given the title Notitia artis musicae and the date 1321 by its publisher, Ulrich Michels, based on a reference made by Johannes de Muris in the explicit to Canones tabulae tabularum (1321). Another title of this musical treatise, Ars novae musicae, comes from the manuscript in the Bibliothèque Nationale in Paris (Lat. 7378 A), which also bears the date 1319. Johannes de Muris gives the incipit of this treatise as “Princeps philosophorum” and refers to it as Summa musicae in a list of books borrowed by Philippe de Vitry (Eskurial, Ms. O.II.10, fol. 225v). In it, Johannes addressed issues that would dominate his entire theoretical and musical work: the principles of the Pythagorean system, to which he devoted Book I, entitled Musica theorica, and the principles of the mensural system, which he presented in Book II, entitled Musica practica. Johannes de Muris’ next musical treatise, Compendium musicae practicae, is an abridgement of Book II of Notitia, written in the form of questions and answers. His next treatise, Musica speculativa, returns to the Pythagorean system and is considered to be an extension of Book I of Notitia. Musica speculativa was edited by Johannes de Muris in two versions: the more extensive version (version A) was written in July 1323, as attested by the explicit of the copy transmitted by the Oxford manuscript (Ms. Bodley 77), while the abridged version (version B) was written in 1325, as stated by the author himself.  There are also other versions known to have been created by combining versions A and B, dating from the second half of the 14th century and the first half of the 15th century.

A summary of Johannes de Muris’ contributions to mensural theory is found in the Libellus cantus mensurabilis, dated to around 1340. The authenticity of this work is beyond doubt, although L. Gushee pointed out that it is mainly transmitted through 15th-century Italian sources. Libellus clearly shows the influence of Philippe de Vitry’s mensural theory, visible, among other things, in the use of red notes and metric markings for modus and tempus. More serious doubts arise regarding the authenticity of the Ars contrapuncti, which, according to Michels, was written after 1340. As K.-J. Sachs has shown, this treatise is clearly divided into two parts: the first (incipit Quilibet affectans) reflects the state of contrapuntal scholarship in the first half of the 14th century and may be the work of Johannes de Muris, especially since it contains a number of formulations consistent with Libellus; the second (incipit Cum notum sit) shows features typical of counterpoint theory in the second half of the 14th century. It cannot be ruled out that Johannes de Muris is also the author of three treatises handed down anonymously in the manuscript Bibliothèque Nationale in Paris (Lat. 7378 A, fol. 58r–59v), containing information on musica theorica, musica mensuralis and discantus.

Johannes de Muris owes his high position in music history primarily to his achievements in mensural theory. He is the first known theorist who attempted to describe and organise the mensural system of ars nova. A measure of his achievements in this field is the Libellus cantus mensurabilis. Johannes de Muris distinguished five rhythmic values (partes prolationis): maxima, longa, brevis, semibrevis, and minima. He defined the relationships between these values as modus, tempus, and prolatio. He fully acknowledged the duple division of rhythmic values alongside the triple division, to which, however, he consistently assigned superiority (in the Notitia he devoted an entire chapter to justifying the perfection of the number 3). In all three of his mensural treatises, he paid particular attention to the problem of imperfection. The chapter of the Libellus devoted to this issue contains a reference to Guillaume de Machaut, the only composer mentioned by Johannes de Muris. Johannes was the first theorist to address the problem of diminution, and he was also the first to introduce and define the concept of the talea. The Libellus also contains the earliest mention in music theory of “empty” notes (replacing red ones). The Libellus cantus mensurabilis was the most frequently copied mensural treatise of the Middle Ages (U. Michels lists 47 copies, only 9 of which originated outside Italy), commented on by Prosdocimus de Beldemandis and Ugolino da Orvieto, among others.

Quilibet affectans z Ars contrapuncti is, in turn, the most widely preserved treatise on counterpoint from the 14th and 15th centuries (K.-J. Sachs lists 12 copies, almost all of Italian provenance). This text is one of the earliest and most fundamental accounts of the principles of counterpoint from the first half of the 14th century. The author distinguished a group of six basic intervals (six species) – the unison, minor third, major third, fifth, major sixth, and octave – dividing them into perfect (unison, octave, and the fifth, which had previously been regarded as a consonantia media) and imperfect (the two thirds and the major sixth), and set out the rules governing their succession. Particularly important are the rules governing the succession of intervals “in a natural way” (naturaliter), as they determine cadential resolutions. For example, after a minor third, a unison should follow; after a major third, a fifth; and after a major sixth, an octave.

The most widely circulated treatise by Johannes de Muris is Musica speculativa, preserved in over 50 manuscripts and 2 prints (the list of 48 manuscripts provided by U. Michels is incomplete). The first version of this treatise is Johannes de Muris’ most extensive text on the Pythagorean system. In the 15th century, Musica speculativa, often referred to as “Musica Muris”, became a compulsory university textbook, gaining particular popularity in Central Europe. From 1406, it was the subject of compulsory lectures at the artes liberales faculty of the University of Krakow, as evidenced by six copies of this treatise preserved in the Jagiellonian Library. Musica speculativa, as Johannes himself stated, is the result of his studies of Boethius’ De institutione musica. As early as the 14th century, it was called “Boethius’ abridgement” (Jacobus of Liège), and this opinion persists to this day. Johannes de Muris actually used only those fragments of Boethius’ work that directly concern the Pythagorean system in its pure, arithmetic form (he omitted, among other things, Boethius’ description of the attempt by the Pythagorean Philolaus to divide the entire tone into two equal parts). He attempted to place this system in the context of Aristotle’s theory of cognition. Musica speculativa is divided into two parts. The first presents, in 18 concise conclusiones, the Pythagorean principle for deriving intervals, based on adding and subtracting the appropriate numerical proportions derived from the tetrad 1:2:3:4. In the final conclusio, Johannes de Muris – as R. Hirschfeld has already noted – questioned the consonant quality of the fourth when, in a three-voice texture, it is placed below the fifth within the span of an octave. In the second part of the Musica speculativa, Johannes de Muris demonstrated a division of the monochord used to determine a 19-note diatonic scale, running from Gamma Graecum to dd duplicatum.

Johannes de Muris’ views had a significant impact on almost all areas of late medieval music theory. Jacobus of Liège, disputing his concepts in the field of mensural theory (especially those concerning imperfection) and the theory of consonance (the issue of the consonant status of the fourth), referred to Johannes de Muris as a “modernus doctor”. This term indicates the role Johannes played in the theory of ars nova music, and the number of surviving accounts of his own works, as well as excerpts, adaptations, commentaries and treatises attributed to him, testify to the fact that this was a leading role. In the 15th and first half of the 16th century, Johannes was even mentioned among the “inventors of music” alongside Pythagoras, Boethius and Guido of Arezzo.

Literature: R. Hirschfeld Johannes de Muris. Seine Werke und seine Bedeutung als Verfechter des Classischen in der Tonkunst. Eine Studie, Leipzig 1884; A. Nagel Das Quadripartitum des Johannes de Muris und das praktische Rechnen im 14. Jahrhundert, “Zeitschrift für Mathematik und Physik” XXXVI, Leipzig 1890; H. Riemann Geschichte der Musiktheorie im IX.-XIX. Jahrhundert, Leipzig 1898, Berlin 2nd edition 1921; E. Déprez Une tentative de réforme du calendrier sous Clément VI. Jean de Murs et la chronique de Jean de Venette, w: Ecole française de Rome, «Mélanges d’archéologie et d’histoire» XIX, Paris 1899; J. Wolf Geschichte der Mensural-Notation von 1250 bis 1460, Leipzig 1904, reprint Hildesheim 1963; P. Duhem Le système du monde, histoire des doctrines cosmologiques de Platon à Copernic, vol. 4, Paris 1916; A. Pirro L’enseignement de la musique aux universités françaises, “Mitteilungen der Internationalen Gesellschaft für Musikwissenschaft” II, 1930; G. Pietzsch Zur Pflege der Musik an den deutschen Universitäten im Osten bis zur Mitte des 16. Jahrhunderts, “Archiv für Musikwissenschaft” I, III, VI, 1936, 1938, 1941, reprint with introduction in: Ergänzungen und neuer Literatur, Hildesheim, New York 1971; H. Besseler, Johannes de Muris, in: Die Music in Geschichte und Gegenwart, ed. F. Blume, Kassel VII, 1958 (extensive list of previous literature); Nan Cook Carpenter Music in the Medieval and Renaissance Universities, University of Oklahoma Press 1958; L. Gushee New Sources for the Biography of Johannes de Muris, “Journal of the American Musicological Society” XXII, 1969; U. Michels Die Musiktraktate des Johannes de Muris, Beihefte zum “Archiv für Musikwissenschaft” VIII, 1970; W. Frobenius Johannes Boens Musica und seine Konsonanzenlehre, «Freiburger Schriften zur Musikwissenschaft» II, Stuttgart 1971; K.-J. Sachs Der Contrapunctus im 14. und 15. Jahrhundert. Untersuchungen zum Terminus, zur Lehre und zu den Quellen, Beihefte zum “Archiv für Musikwissenschaft” XIII, 1974; M. Haas Musik zwischen Mathematik und Physik. Zur Bedeutung der Notation in den “Notitia artis musicae” des Johannes de Muris (1321), in a commemorative book for A. Volk, Cologne 1974; F. della Seta Scienza e filosofia nella teoria musicale dell’Ars Nova in Francia, “Nuova Rivista Musicale Italiana” X, 1976; A. Gallo Znajomość “Musica speculativa” Johannesa de Muris w Polsce i we Włoszech. Glosy Uniwersytetu Krakowskiego i “Glossemata” Franchina Gaffuriusa, «Pagine» III, 1979; Ch. E. Brewer “Musica Muris” w krakowskich rękopisach z XIV i XV wieku, “Muzyka”, Warsaw 1980 no. 3; F.A. Gallo Die Notationslehre im 14. und 15. Jahrhundert, in: Die mittelalterliche Lehre von der Mehrstimmigkeit, Geschichte der Musiktheorie, vol. 5, ed. F. Zaminer, Darmstadt 1984; E. Witkowska-Zaremba Aspekt praktyczny traktatu “Musica speculativa” Johannesa de Muris, “Studia Mediewistyczne” XXIV, 1985 iss. 1.; E. Witkowska-Zaremba Music between Quadrivium and Ars Canendi: Musica speculativa by Johannes de Muris and its Reception in Central and East-Central Europe, in: Cantus Planus IV, Pécs 1990; E. Witkowska-Zaremba “Musica Muris” i nurt spekulatywny w muzykografii średniowiecznej, Warsaw 1992; L. Gushee “Jehan des Murs and His Milieu”, Musik und die Geschichte der Philosophie und Naturwissenschaften im Mittelalter: Fragen zur Wechselwirking von “musica” und “philosophia” im Mittelalter, ed. F. Hentschel, Leiden 1998; F. Hentschel Sinnlichkeit und Vernunft in der Mittelalterlichen Musiktheorie,  “Archiv für Musikwissenschaft” XLVII, Stuttgart 2000; Ch. Meyer … per venerandae memoriae magistrum Iohannem de Muris…La tradition parisienne de l’enseignement de Jean de Murs, in: commemorative book for Walter Pass, ed. M. Czernin, Tutzing, 2002; K. Desmond Music and the moderni, 1300–1350. The ars nova in Theory and Practice, Cambridge 2018; K. Desmond Jean des Murs and the Three Libelli on Music in BnF lat. 7378A: A Preliminary Report, “Erudition and the Republic of Letters” 4, 2019; E. Witkowska-Zaremba Between Intellectus, Visus and Auditus: Jean des Murs’s Musica Speculativa, Version A (1323), “Erudition and the Republic of Letters” 4, 2019; E. Witkowska-Zaremba Johannes de Muris’s Musica Speculativa cited by Jacobus de Ispania, “Plainsong and Medieval Music” 31/1, 2022.