Tradition attributes particular steps in the process to certain popes, bishops and other ecclesiastics. Two names have been specially emphasized, Bishop Ambrose of Milan (d. 397) and Pope Gregory the Great (d. 604), the latter being constantly put forth as the founder and organizer of the whole style called 'Gregorian.' But these traditions, as commonly stated, are at least doubtful. Many able scholars believe that the practical completion of the system was not earlier than the 8th century, perhaps under Gregory II. (d. 731) or Gregory III. (d. 741), and that the name 'Gregorian' either came from them or was due to the mistaken zeal of those who sought to glorify the earlier Gregory.
It should be remembered that the Gregorian style is the property of the Western or, more exactly, the Roman Church. In each of the other branches of the early Church there were analogous developments, but none of these, except to a very limited extent that of the Greek or Russian Church, has any significant connection with the story of modern music.
Since the Gregorian style originated for liturgical reasons, its
home was the metropolitan cathedral or the monastic chapel,
whence it spread to parish churches generally. Being cultivated
only by ecclesiastics, to the common people it was remote and
abstruse. Its direct influence upon the general progress of music
was therefore limited. To some extent there arose an antipathy
between it and secular music, which was heightened by the fact
that church song was always in Latin. In the general evolution
of music it has always remained a somewhat peculiar specialty,
representing the persistence for a particular purpose of a style
which is essentially antique. Yet it must be confessed that in
its ideal perfection, as it stood in the early Middle Ages, it was
a remarkable example of melodic invention and beauty.
The Gregorian style is the only form of music prescribed for use in
the Roman Church, though some other styles have been allowed or tolerated.
It is supposed, however, that its extensive treasures represent
several stages of production, and all are not of equal validity. In a general
way, the over 600 melodies belonging to the Mass and certain
other principal rites have the greatest antiquity, while the almost 3000
belonging to the Breviary are later, and those fitted to hymns or sequences
later still. But during the Renaissance the whole series was
treated with much freedom, especially in the matter of embellishments
and ornate expansions, so that in the 16th century, when Gregory XIII.
and Sixtus V. ordained the service-books since in use, the style was no
longer pure. Recent enactments of Pius IX. (1869), Leo XIII. (1883)
and especially Pius X. (1903) have aimed not only to enforce the rules
enjoining the use of Gregorian music almost to the exclusion of other
styles, but to correct many abuses in its habitual rendering and ultimately
to recover and restore its typical forms. Especially under the