lead of the monks of Solesmes (see sec. 227) fresh efforts are now being put forth to establish authentic texts and correct renderings.
Gregorian melodies vary considerably according to the kind
of text for which they are designed and to the period they represent.
Some are merely monotones with occasional inflections.
Some, as a rule, have but one tone to the syllable and move chiefly
by diatonic steps. Some abound in flowing figures to single
syllables and in skips, large or small. But, whatever their form,
they plainly show a desire to find a real tonal embodiment for
the words and the thought. Only comparatively late came in
the desire to make tonal patterns for their own sake. Being
designed primarily for prose texts, they have no fixed rhythm or
standard length of tones. Accents and quantities are derived
from the words, after the manner of recitative, and in good rendering
expressive flexibility is conspicuous. The compass is
rarely greater than an octave and is often much less. The selection
of tones conforms to scale-types differing from those of
secular and modern music generally (see sec. 27). Properly,
the unison should not be accompanied, since harmony introduces
a somewhat foreign element and, unless very dexterous, totally
changes the effect.
The term 'Plain-Song,' often applied to Gregorian music, emphasizes
either its lack of fixed rhythm (in contrast with 'Measured Music'), or
its lack of harmony or part-writing (in contrast with 'Figured Music'
or 'Counterpoint').
27. Its Technical System.—That the tone-system of the
Middle Ages came from that of the Greeks is evident, though
the stages of evolution are not entirely clear. But probably the
formal system was at first more implicit than consciously formulated.
Only after Plain-Song had reached a considerable
development was an effort made to arrange its principles systematically.
The basis chosen was a series of modes resembling
the 'species' of the Greeks. Prior to about 1000 the
accepted modes numbered eight, which later came to be known
by Greek names (oddly transposed from their ancient meaning).
These modes fall into two classes—the 'authentic' (straight or
primary) and the 'plagal' (oblique or derived), the former having
the 'final' (somewhat analogous to keynote) at the bottom
and the 'dominant' (chief reciting-tone) in the middle, while
