The keynote of the reform of St.
Gregory was fidelity to the traditions that had been handed down
(the root meaning of the Latin word traditio is to hand
over or hand down). His reform consisted principally of the simplification
and more orderly arrangement of the existing rite,the
reduction of the variable prayers at each Mass to three (Collect,
Secret, and Postcommunion), and a reduction of the variations
occurring at that time within the Canon,
prefaces and additional forms for the Communicantes and
Hanc Igitur. These variations can still be found on a
very few occasions such as Christmas and Easter. His principal
work was certainly the definitive arrangement of the Roman Canon.
The Lectionary was also given a definitive form, but was still
to undergo considerable change subsequently. The Order of Mass
as found in the 1570 Missal of St. Pius, apart from minor additions
and amplifications, corresponds very closely with the order established
by St. Gregory. It is also to this great Pope that we owe, to
a large extent, the codification of the incomparable chant that
bears his name.