The Spirit of Gregorian Chant - Church Music Association of America

46 THE SPIRIT OF GREGORIAN CHANT
Among the letters used in this manuscript to help determine the
intonation of the neums is found a supplementary sign (|—), con"
sisting of two lines, diversely placed against one another according
to the note for which the sign substitutes at places where a half'
tone exists. The quarter'tone, the diesis, for which this episema
(Gr. episema, mark or sign) is sometimes deciphered, was, according
to Dom Pothier, probably particular only to the discourse of
the ancients; for, he asserts, their delicate appreciation of tones and
sense of euphony might well have designated by a quarter'tone in
music that which corresponded at its origin to the ordinary music
of discourse. Even in the most precise melodies one can find pas'
sages which seem to approach vaguely the tone of simple speech,
passages where one recognizes the quarter'tone of the spoken word
without the song ceasing to belong to a really diatonic order. 1 An'
other authority maintains, however, that this episema does denote
a quarter'tone. 2
Gregorian Chant was at first entrusted to the memory of the
singers and to tradition by oral training. Neums were used merely
for recalling to the memory that which was already known, just as
Hebrew mnemonic signs suffice for the cantor. 3 Neums were, how
ever, insufficient at their origin for transmitting integrally an un'
known melody.
It took years for the early medieval chanter, by work and perse'
verance, to know the Antiphonary. To assist his memory he used
timbres (fixed melodies). Guido, in describing these, points out the
fact that there are eight Modes as there are eight parts of speech and
eight Beatitudes, and that each Mode has its special nuances. In
order to distinguish the Modes, eight Tone phrases were composed,
each one with special characteristics of a particular Mode. These
familiar melodies were compared with the unknown melody to reveal
the Mode of the latter. These model melodic types were fitted to
words from Holy Scripture, and had long tonal formulas of Byzantine
style. They were employed by the chanters merely as prototypes
for practice work, and not for liturgical use, and are found in
*Les Mel. Grig., Ch. III. 2 J. Gmelchs, Die Viertelstonstufen im Messtonale von Montpellier, Ref.,
New School of Greg. Chant, Ch. II, Part 2. »Les Mel. Grig., Ch. III.