But while this remarkable run ends the composition, very narrowly defined, it does not end the
Alleluia, or even the verse. The chorus must sing its brief response (including the melisma on the name of
“David” that recapitulates the melody of the jubilus, the enormous melisma at the end of the choral
repetition of the word “Alleluia”; it, too, will figure again in a later chapter). And then the whole Alleluia
with jubilus must be repeated, either with polyphony (as some of the sources direct) or without. A
polyphonically outfitted liturgical chant as sung at Notre Dame, though far more elaborately composed
than any other polyphonic music of its time, is still not a composition in our modern sense. It is not solely
the product of an author’s shaping hand but the complex response to a variety of ceremonial and artistic
demands, some seemingly in mutual contradiction.
THEORY OR PRACTICE?
The most authoritative source for our knowledge of the epochal rhythmic practices of the Notre Dame
School is the treatise De mensurabili musica, written around 1240 by Johannes de Garlandia. He was a
lecturer (magister) at the University of Paris, possibly the very one from whom the author of Anonymus
IV learned what he passed on to us. His name derives from his university affiliation: the clos de Garlande
was a colony on the left bank of the Seine where many members of the university arts faculty made their
homes.
De mensurabili musica (“On measured music”) was one of two textbooks Johannes wrote for the