ion that would ensue if the rest
[illustration] stood for [fusa]. Besides, the sign would have
easily become confused with the C clef [illustration].

Signs for the changes of _tempo_, that is to say changes
from quick to slow, etc., were introduced in the fifteenth
century. The oldest of them consists of drawing a line through
the _tempus_ sign [O|]. This meant that the notes were to be
played or sung twice as rapidly as would usually be the case,
without, however, affecting the relative value of the notes
to one another. Now we remember that the sign [C] stood for
our modern [4/4] time; when a line was drawn through it,
[C|] it indicated that two _brevi_ were counted as one, and
the movement was said to be _alla breve_. This is the one
instance of time signatures that has come down to us unaltered.

IX

THE SYSTEMS OF HUCBALD AND GUIDO D'AREZZO--THE BEGINNING
OF COUNTERPOINT

We have seen that by order of Charlemagne, Ambrosian chant was
superseded by that of Gregory, and from any history of music
we may learn how he caused the Gregorian chant to be taught
to the exclusion of all other music. Although Notker, in the
monastery of St. Gall, in Switzerland, and others developed the
Gregorian chant, until the time of Hucbald this music remained
mere wandering melody, without harmonic support of any kind.

Hucbald (840-930) was a monk of the monastery of St. Armand in
Flanders. As we know from our studies in notation, he was the
first to improve the notation by introducing a system of lines
and spaces, of which, however, the spaces only were utilized
for indicating the notes, viz.:

[Illustration]

His attempt to reconstruct the musical scale was afterwards
overshadowed by the system invented by Guido d'Arezzo, and it
is therefore unnecessary to describe it in detail. His great
contribution to progress was the discovery that more than one
sound could be played or sung simultaneously, thus creating a
composite sound, the effect which we call a chord. However,
in deciding which sounds should be allowed to be played or
sung together, he was influenced partly by the mysticism of
his age, and partly by a blind adherence to the remnants of
musical theory which had been handed down from the Greeks. As
Franco of Cologne, later (1200), in systematizing rhythm into
measure, was influenced by the idea of the Trinity in making
his [3/8] or [9/8] time _tempus perfectum_, and adopting for
its symbol the Pythagor