Gregory
Gregorian chant is a recension of the corpus of chant built up over a long period of time
in Rome and later Metz and which was spread by Frankish kings throughout Western
Europe. The above quote, "Gregory the prelate compiled this little book of musical art
for the chant schola for the annual cycle," comes from the earliest surviving graduals
(chant books) from the 780s. There are three popes of the name by that date, Gregory
the Great (590-604), Gregory II (715-731) and Gregory III (731-741).
The bulk of the chant corpus seems to have established itself by about 600AD. Around
the same date, the introduction of Advent completed the basic church year as we know it
and chants for new festivals instituted after that date appear in the main to have been
assigned from the existing corpus. The addition of the Agnus Dei (Lamb of God) by
Sergius 1 (687-701) marks an important cut-off point in the introduction of new chants in
Rome and this excludes the later popes as candidates for overseeing the introduction of
the basic chants of the established Roman liturgy. The chant itself uses the text of the
old Latin psalter which was generally replaced in Rome in the early 7th century by a
revised version, probably by Jerome, whereas the Franks adopted Jerome's translation
from the Greek.
Gregorius presul composuit hunc libellum musicae artis scholae cantorum
per circulum anni