notation, from the Notre Dame manuscript W 2 . Fig. 7-2 bshows the duplum from the same clausula in
prosulated form, as it is found in a different fascicle of W 2 . The syllabic text it now carries is a Latin
poem honoring both the Virgin Mary’s birth and that of her son. It opens with a quotation from the text of
the Marian Alleluia verse Nativitas at the very point where the clausula begins (Ex semine Abrahe, “from
the seed of Abraham”), and closes with a repetition of the word semine. These, along with yet an
additional allusion to the Alleluia text, are italicized in the following transcription of the prosula-poem:
Thus the prosula-poem is a textual interpolation into the canonical chant as well as a potentially self-
contained song. It is a gloss on the text of the Alleluia in the manner of a trope, and was probably meant
for insertion directly into a performance of the organum. (But note that Fig. 7-2b also contains the tenor,
so that the texted clausula can also be performed independently of the chant and its other polyphony.)
Since it is now notated cum littera like the conductus studied at the end of the previous chapter, the
duplum can no longer use the first-mode ligatures of the clausula. It is now a motellus (later, and more
standardly, a motetus), a “texting” or a “wording” or a “part with words.” The term itself is a curious
Latin back-borrowing from French, in which mot is the word for “word.” Anyone actually inserting the
motetus into the organum would have to know the rhythms of the clausula by heart. So at this stage a
prosulated discant or motet has to be notated twice: once for the tune, again for the text.
Indeed, when motets, freshly weaned from their incubator within the organum, began to be written as
new, freestanding pieces of texted music rather than mere textual grafts on existing discants, they still
needed at first to be notated twice, syllabically for the words and melismatically for the rhythm. The only
reasonable explanation for the extravagant excess of discant clausulae one finds in the Notre Dame
sources—as many as two dozen or more for a tenor that might only be sung liturgically once a year—is
that many or most of these “clausulae” were actually rhythmic templates to guide the performance of
already-composed motets. What this also shows is that one must take care to distinguish between the
chronology of genres and that of individual pieces. The fact that the clausula as a genre precedes the motet
as a genre in no way implies that any given untexted clausula must have preceded its texted counterpart or
counterparts. The latter may indeed be prosulated versions of the former, but the former may just as easily
be an aid to assist in performing the latter.
Now compare Fig. 7-3, a page from a later manuscript that contains nothing but motets. It is the same
clausula on Ex semine, now given complete, in all three parts. The motetus, or texted duplum shown in
Fig. 7-2b occupies the right hand column. Under it is the familiar tenor. Opposite it, in the left column, is
the triplum from the clausula (compare Fig. 7-2a), now also outfitted with a text—another text! It is
another gloss on the text of the same Alleluia, reflecting and enlarging, like its counterpart, on the marvel