Steven F.Kruger
[See also: CHARLES V THE WISE; CURRENCY; TRANSLATION]
Oresme, Nicole. De proportionibus proportionum and Ad pauca respicientes, ed. and trans.
Edward Grant. Madison: University of Wisconsin Press, 1966.
——. Le livre de politiques d’Aristote, ed. Albert Douglas Menut. Philadelphia: American
Philosophical Society, 1970.
——. Nicole Oresme and the Medieval Geometry of Qualities and Motions: A Treatise on the
Uniformity and Difformity of Intensities Known as Tractatus de configurationibus qualitatum et
motuum, ed. and trans. Marshall Clagett. Madison: University of Wisconsin Press, 1968.
Hansen, Bert, ed. and trans. Nicole Oresme and the Marvels of Nature: A Study of His De causis
mirabilium with Critical Edition, Translation, and Commentary. Toronto: Pontifical Institute of
Mediaeval Studies, 1985.
Menut, Albert Douglas. “A Provisional Bibliography of Oresme’s Writings.” Mediaeval Studies 28
(1966):279–99; supple mentary note, 31 (1969):346–47.
ORGANUM
. During the 12th century, improvised and composed or notated vocal polyphonic music
began to take on a distinct stylistic change that ultimately divided it into two types. In
discant, one or more parts were added mostly note-against-note to a plainchant melody,
possibly moving in parallel motion but often in contrary motion with it; in organum, one
part embellished with many notes each note of the plainchant, thus slowing it down
considerably and making it, at its most ornate, unrecognizable. The limitation to which
organum, described as an “infinitely flexible” art, was subject was that there could be but
one performer of the added part, and therefore it would have been impossible to
coordinate adequately between two or more singers. Organum was an almost perfect
medium for virtuoso solo singing and improvising, in contrast to discant, in which
interaction among singers (one to a part), a sense of ensemble, was the primary
requirement. The singer of the plainchant played a role of support by sustaining each note
of the chant until he coordinated the next one with the soloist, and organum that survives
in notation is always in score so that the correlation of the two parts can more readily be
seen.
These two different styles of polyphony, discant and organum, were nevertheless
generically called “organum,” and thus the polyphony for the Graduals, Alleluias, and
Responsories of the Notre-Dame repertory are termed “organa,” including the organa for
three and four parts. Theorists of the 13th century who discussed “measurable music”
(musica mensurabilis) divided this generic organum into three categories, most often
discant, copula, and organum, the last being called organum purum or organum in
speciali. These are not three types of pieces of music, however, but the three styles or
musical textures that could be found within the polyphony for a Gradual, Alleluia, or
Responsory. In time, genres became categorized as species of discant—e.g., the motet—
and there seem to be such ties between copula and hocket that need further elucidation.
The Magnus liber organi for the cathedral of Notre-Dame in Paris was, in its original
form, apparently mostly in organum style, since its compiler, Léonin, was called optimus
Medieval france: an encyclopedia 1290