storical character, for if it had been a mere vague tradition
in glorification of St. Gregory, he would have been more likely to have
spoken of him as the composer of the Antiphoner, and not as a mere
compiler. The oldest part of the book is formed of the Feasts celebrated
in honour of events and saints spoken of in Scripture, and of the oldest
Roman Saints. The Masses for these are taken from Scripture, especially
from the Psalms. For Feasts of non-Roman origin, the text is taken from
the Church from which they are introduced; _e.g._, the Feast of St.
Agatha from the Sicilian Church, or the Feasts coming from the Greek
Church which were translated from the Greek. The want of uniformity in
the arrangement of the text is seen by comparing the different classes of
chants in _Codex St. Gall_, 329. As a rule, the words of one and the same
Mass are all of different origin. The most ancient part of the Masses is
the Graduals and Tracts, and all these (which are the most ancient solos
of the Mass) in the Gregorian nucleus are taken from Biblical sources.
This part of the "cento Antiphonarius" is put together in one system
after an established tradition. In the oldest Feasts there are
Psalm-graduals, but Introits taken from other books of the Bible. The
parts other than the Gradual and Tract were chosen on a different system,
a considerable number in fact have words not taken from the Bible at all.
The Communions, again, form a class by themselves, and were sometimes
chosen with special reference to the Gospel for the day, which is the
case with no other class of the texts of the chants.

Now this editing of the texts must have implied the editing of the music
also. In the middle ages the choir played a more important part than they
do to-day in the Roman Church. For now the Service is complete without
their part, as the priest says the whole Service whether the choir is
there or not. But formerly it was different; all listened or took part,
including the celebrant, while the choir sang. The latter had a very
definite share in the liturgical order, which was incomplete without
them; in particular, the soloists had full scope for their talents in the
chants between the Epistle and Gospel. In view of this intimate relation
between the choir and the altar, a revision of the text must almost
necessarily have implied a revision of the music. And this is probably
the chief part of his musical reform; in the saying about him, ascribed