The most spectacular Mass in Palestrina’s third book, though, and the most telling instance of
emulation, is his Missa Repleatur os meum laude (Mass on “May my mouth be filled with praise”),
ostensibly based on a motet by Jacques Colebault (1483–1559), a French composer who worked in Italy
and was known there as Jacquet (or Jachet) of Mantua. Jacquet’s motet was itself a contrapuntal tour-de-
force, embodying throughout a chant-derived canon at the fifth between the “structural” voices. Palestrina,
using the same basic material, constructed a vast canonic cycle in which both the pitch interval and the
time interval progressively contract toward unison. In the Kyrie, sampled in Ex. 16-3, the opening section
has a canon at the octave at a time lag of eight semibreves.
EX. 16-2B Missa super Ut re mi fa sol la, final Agnus Dei