specifically and technically to medieval polyphony.
POLYPHONY IN AQUITANIAN MONASTIC CENTERS
By the time the word discant became current, a new style of organum had arisen in contrast to it. This new
style resembles some of Guido’s examples (which may have helped inspire it) in that one voice is
relatively stationary while the other moves freely, creating a variety of intervals against the first. The
great difference is that in the new style the dronelike voice is the vox principalis, and the vox organalis is
the moving voice—or, as we now should call it, the melismatic voice, since it sings several notes against
each syllable-carrying note of the original chant. Hand in hand with this difference went another just as
big: the vox principalis is now the lower, not the upper voice.
What brought about these momentous practical departures? They amount virtually to standing the older
polyphonic texture on its head: what was top is now bottom; what was mobile is now stationary, and vice
versa. And perhaps most important from the listener’s perspective, what had been subordinate (namely,
the added voice) is now dominant. In the new melismatic organum, the chant seems paradoxically to
accompany its accompaniment.
In keeping with this changed perspective, a new terminology is warranted, one that will remove the
apparent paradox. Instead of vox principalis, let us simply call the voice that sustains the long-held notes
of the original chant the “holding part.” Since the Latin infinitive “to hold” is tenere, the chant-bearing
part will henceforth be known as the tenor. The word actually begins appearing in this sense in the
treatises of the thirteenth century, and though its meaning has varied over the years, it is still an important
musical term today. This was its first meaning for polyphonic music—the voice that holds a preexistent
melody out in long notes over which another voice sings a florid counterpoint. It was the relegation of the
chant melody to the tenor that was the new event, for it inaugurated a texture—and a procedure—that
would last for centuries. Indeed it is still practiced (or at least administered), under the thirteenth-century
name cantus firmus or “fixed tune,” in academic counterpoint studies today. For a sample of the new
texture see Fig. 5-2.
This composition is from a manuscript that dates from around 1100 and was long kept in the library of
the biggest Aquitanian monastery, the Abbey of St. Martial at Limoges. Its Aquitanian origin and its
association with St. Martial is already a clue to the new style’s why and wherefore, for we have
encountered St. Martial before, as a center of trope and versus composition. The tenor in Fig. 5-2 is in
fact a metrical versus composed to adorn the end of Christmas matins. What is melismatic organum then
but an adornment of an adornment, a polyphonic gloss? It is a longissima melodia (to recall some
terminology from chapter 2) sung not in place of an older chant, or in between its phrases, but (imagining
two singers now) literally alongside it. “St. Martial”-style polyphony is thus a new kind of trope,
simultaneous rather than prefatory, and a literal (that is, sonic) amplification of the liturgy.