heterogeneous complexity in all of its historical and technical dimensions is beyond the scope of a chapter
like this, but sampling the strikingly contrasting Kyrie (Ex. 9-15) and Gloria (Ex. 9-16a), the only sections
of the Ordinary that are performed in direct sequence, will in their very contrast at least register the
Mass’s stylistic extremes. The little dismissal response (Ex. 9-17) has been thrown in, too, as a reminder
of the Mass’s modal heterogeneity, and its consequent status as an irreducible sum of functional parts
rather than the kind of unified whole we may be more in the habit of seeking (and therefore finding) in a
work reputed to be a masterpiece.
EX. 9-15 Guillaume de Machaut, La messe de Nostre Dame, Kyrie, mm. 1–27