JACQUES DE LIÈGE
(Jacobus Leodiensis; ca. 1260-after 1330). Author of the Speculum musice and other
works on music theory. Little is known about Jacques’s life. He has been identified with
one Jacobus de Oudenaerde, a canon of Liège and, in 1313, a professor at Paris.
Jacques’s early education in music was in the theories of Franco of Cologne and later
Boethius, whose De institutione musica he studied at Paris. It was there that the Speculum
musice was begun, an encyclopedic discussion of speculative music (five books, in which
he draws upon the authority of Plato, Boethius, Isidore, Guido d’Arezzo, and John of
Afflighem, as well as Aristotle, Robert Kilwardby, Peter Comestor, Johannes de
Garlandia, and Franco of Cologne), ecclesiastical chant (one book, treating both Boethian
and Guidonian modal theory), and measured music (one book, describing the genres of
discant composition and discussing notation). The last two books of the Speculum reveal
connections with Liège sources and might have been composed in that city. Book 7 was
composed chiefly to refute the teachings of the Ars Nova school on rhythm and notation,
vindicating such traditional theorists as Franco of Cologne and Magister Lambertus.
Overall, Jacques’s work is the most cogent and complete statement of the theory and
practice of the Ars Antiqua. The Speculum musice was formerly attributed to Jehan des
Murs, but many of its doctrines contradict Jehan’s teaching.
Tony Zbaraschuk
[See also: ARS ANTIQUA; ARS NOVA; FRANCO OF COLOGNE; JEHAN DES
MURS; JOHANNES DE GARLANDIA; MUSIC THEORY]
Jacques de Liège. Speculum musicae, ed. Roger Bragard. 7 vols. Rome: American Institute of
Musicology, 1955–70.
JACQUES DE VITRY
(ca. 1160/70–1240). The son of a wealthy bourgeois family in Vitry-en-Perthios near
Reims, Jacques studied in Paris at a time when Peter the Chanter, one of the most
celebrated preachers of his day, was master of the cathedral school. In 1211, he entered
the monastery of Augustinian regular canons dedicated to St. Nicolas in Oignies, not far
from Cambrai. Over the next five years, he was close to the lay religious group known as
the béguines, whose leader was Marie d’Oignies. During this same period, he became a
preacher of crusades, first against the Albigensians in 1213 and then against the infidels
in the Holy Land in 1214. His preaching won him the see of Acre on the coast of
Palestine. Jacques arrived in Palestine in 1216 and accompanied the armies of the Fifth
Crusade at Damietta, 1218–21. Weary of constant strife, Jacques left Acre in 1225 and
served Pope Gregory IX in Italy and in the Low Countries over the next three years. In
1228, Gregory appointed him cardinal bishop of Tusculum, and he remained in Rome
until his death. Jacques was buried at the monastery in Oignies, where he had begun his
ecclesiastical vocation.
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