ses crept in through
the adoption of local secular melodies not yet divested of their
profane associations. St. Gregory the Great (540-595), who was elected
pope about 590, set himself to restore church music to its purity, or
rather to restrict the introduction of profane melodies, and to
establish certain limits beyond which the music should not be allowed
to pass. St. Gregory himself was not a musician. He therefore
contented himself with restoring the Ambrosian chants as far as
possible; but the musical scales established by Ambrose he somewhat
enlarged, adding to them four other scales called plagal. These were
the Hypo-Dorian, la to la; Hypo-Phrygian, si to si; Hypo-Lydian, do to
do; Hypo-AEolian, mi to mi. I do not understand that the terminal notes
of these plagal scales of St. Gregory were used as key notes, but only
that melodies instead of being restricted between the tonic and its
octave, were permitted to pass below and above the tonic, coming back
to that as a center; for we must remember that in the ancient music
the tonality was purely arbitrary, and, so to say, accidental. While
all kinds of keys used the series of tones known by the names do, re,
mi, fa, so, la, si, do, it was within the choice of the composer to
bring his melodies to a close upon any one of these tones, which,
being thus emphasized, was regarded as the tonic of the melody.
Whatever of color one key had differing from another was due therefore
to the preponderance of some one tone of the scale in the course of
the melody. The Plain Song of the Roman Church, and of the English
Church as well, has been called Gregorian, from St. Gregory, and the
majority of ecclesiastical amateurs suppose that the square note
notation upon four lines was invented by St. Gregory. This, however,
is not the case. The melody, very likely, may have come down to us
with few alterations. The notation, however, has undergone several
very important changes, of which there will be more particular mention
in chapter XV. The Gregorian notation of the sixth century was
probably the Roman letters which we find in Hucbald, as will be seen
farther on. Several of the tunes well known to Protestants have been
arranged from the so-called Gregorian chants. They are "Boylston,"
"Olmutz" and "Hamburg." The eighth tone, from which "Olmutz" was
arranged, has always been appropriated to the _Magnificat_ ("My Soul
doth Magnify the Lord").

The following are the ecclesiastical sc