structural divisions of the chant. The break between Leonel’s two major sections occurs in the middle of a
ligature, and the end of the cantus firmus also comes in the middle of a word; nor is the last note of the
cantus firmus even the final of the original melody’s mode.
EX. 12-2A Alma Redemptoris Mater (eleventh-century Marian antiphon)Thus there is no apparent rhyme or reason for Leonel’s selection or apportionment of his cantus firmus
material. That is not to say that there was no reason, only that it is not readily apparent. Possible reasons
might have involved numerology or some other form of occult symbolism, or might have had some other
connection with musica speculativa. Sometimes modern researchers stumble on these things, and
sometimes they don’t. In any case, the absence of an apparent rationale is not proof of the absence of a
rationale. Nor is it proof of the presence of a rationale. Sherlock Holmes and his famous dog that failed to
bark in the night notwithstanding, one can rarely make secure deductions from an absence. (It follows,
then, that we can never know that a given piece of music has no preexisting cantus firmus; all we can
know is that we have not yet discovered one.)
What is possible to say with certainty is that, whatever the reason for it, Leonel’s selection and
apportionment of raw material for his cantus firmus was entirely arbitrary (that is, “at will”), unrelated to
the formal or semantic content of the antiphon from which it came. Similarly arbitrary is the processing of
the raw material. Ex. 12-2b shows the actual tenor of Leonel’s Mass in its entirety and in the original
notation. The two sections marked I and II are cast in contrasting mensurations. (The first section, in
accordance with an English custom for the use of major-prolation signatures in notating tenors that a few
continental composers picked up, is meant to be performed “in augmentation,” that is, in durations twice
as long as those written.) The rhythms show an effort to include maximum variety. There is a profuse and
unpredictable mixture of note values, including such standard options as hemiolas in the first (perfect)
section and syncopations in the second (imperfect) one.
EX. 12-2B Tenor of Leonel Power’s Mass on Alma Redemptoris MaterOnce established, this arbitrary color/talea combo was cast in stone. It serves as the basis for all four