series of ternariae followed by a nota simplex.)
Garlandia’s sixth mode, too, is more or less notional, included on Villedieu’s authority as a
complement or balance to the fifth, which of course has a long history in practice. Brief passages in
uniform breves are found in many compositions of the “Notre Dame school.” They can be just as easily
notated (with plicas, for example) without any special mode. There is one famous passage in an Alleluia
attributed in Anonymus IV to Perotin that has a few ordines ostensibly in Garlandia’s sixth mode and
using the notation he assigns to it. But the passage could as easily have been written in “fractured”
trochees (first mode), and might very well have actually been written that way in its earliest sources.
That would mean that Garlandia’s treatise, which purported to describe a musical practice, ended up
prescribing one instead. The same possibility, that the theorist influenced the composition style he
ostensibly reported involves the second mode (iambic) as counterpart to the ubiquitous first. We have
seen an example of the second mode in practice, in one of the spare “DO-” clausulas from the Florence
manuscript (Ex. 6-3d). But that manuscript was compiled after Garlandia’s treatise had become a
standard text, and there is little or no evidence for the use of Garlandia’s second mode at any earlier time.
What we seem to have in Garlandia, then, is a summary of an actual rhythmic practice that was more
or less confined to three patterns (trochaic, dactylic, and spondaic), corresponding to Garlandia’s odd-
numbered modes. And then there is a supplementary, even-numbered, trio (iambic, anapestic, tribrachic)
that were there for the sake of the theory—but that were later incorporated to some extent into practice
under the influence of the theory. It is an excellent paradigm or instructive model for considering the
complex relationship that usually obtains between theory and practice.
Theory is almost never pure description. It is usually a representation not of the world the theorist
sees but of a more orderly, more easily described world the theorist would like to see. A persuasive
theory, particularly one of suggestible human behavior or practice, can often to some extent reshape the
world to conform, for better or worse, to the utopian image. But an attractive theory uncritically accepted
can also blind the believer to existing conditions, and lessen rather than enhance comprehension.
Uncritical acceptance of Garlandia’s six-mode scheme can obscure the actual history of musical practice
at Notre Dame, and that is why it should be regarded as a secondary rather than a primary source of
knowledge.
CONDUCTUS AT NOTRE DAME
The remaining polyphonic genre practiced at Notre Dame was the conductus. Its status there was far more
modest than at previous monastic polyphonic centers, but well over a hundred conductus nevertheless
survive, in two, three, and four voices.
Conductus was exceptional among Notre Dame genres in that it was not based on a preexisting chant,
but was a setting of a contemporary poem, potentially composed from scratch. Contemporary theorists
described the method of composing a conductus in terms as close as possible to those governing discant
composition, however. Franco of Cologne, with whom we will become better acquainted in the next
chapter, wrote that anyone wishing to compose a conductus should first “invent as beautiful a melody as
he can,” and then “use it as a tenor for writing the rest.”^8 Sometimes, indeed, conductus are found in both
monophonic and polyphonic versions; and when this is the case, the melody that exists alone is almost
always the tenor in the polyphonic variant, confirming Franco’s prescription. But the texture of a
conductus, while basically homorhythmic (note-against-note) can also be well enough integrated by means
of hockets and voice exchanges to suggest that not all composers relied on the “write-your-own-cantus-
firmus” method.