Music from the Earliest Notations to the Sixteenth Century

This is definitely an “art” setting, if a relatively unshowy one, and literate through and through, worlds
away from the bald, nonfigural “sight” harmonization in Ex. 11-21. The artfulness is most apparent in the
rhythmic design, which has been calculated with great subtlety both as to declamation and as to variety.
The basic mensuration is that of tempus perfectum—semibreves grouped by threes into perfect breves.
But Binchois applies hemiola at two levels, one above the basic mensuration (at the level of modus) and
one below (at the level of prolatio). For an example of the latter, see the setting of the word gratia, where
the cantus breaks momentarily into a trochaic pattern of semibreves and minims (quarters and eighths in
transcription) that implies a grouping of three minims into perfect semibreves. And for the former, see
what the tenor does immediately afterward (on quae tu creasti), where a series of imperfect breves (half