change in all modern music—the mediant keys being those sit-
uated half-way between a Tonic and Dominant or a Tonic and
Subdominant,e.g.
[Music: Sub-mediant Mediant]
Anyone at all familiar with Beethoven’s style will remember how
often his second theme, instead of following the more conven-
tional line of dominant relationship, is in a mediant key. Good
examples may be found in the first movement of theWaldstein
Sonataand in the first and last movements of the 8th Sym-
phony. A little thought will make clear that the relationships
just set forth include nearly all the possible ones save those of
2nds and 7ths. Even into these apparently distant keys,e.g.,
to D-flat major or to B major from C major, modulations may
easily be made by means of the “enharmonic"[50] relationship
found in that frequently used modern chord—the Augmented
Sixth,e.g.
[Music: C major B major C major D-flat major]
[Footnote 50: Two tones are said to be “enharmonic” when,
although written differently, they sound the same on an instru-
ment of fixed temperament like the pianoforte, or organ,e.g.,
D-sharp and E-flat, E and F-flat. A violin, however, can make
a distinction between such notes and often does.]
Next to rhythm, modulation is the most stimulating and en-
chanting element in music. No composition of any scope can
be considered truly great unless it abounds in beautiful mod-
ulations. Certain composers, to be sure, have in this respect
more genius than others—notably Schubert, Chopin, Wagner
and Franck whose music seems to waft us along on a magic car-
pet of delight. But just as Unity depends upon a definite basic
tonality, so Variety is gained by this very freedom of modulation.
Without it is monotony; with too much modulation, an irritat-
ing restlessness. By the perfect balance in his works of these
two related elements a genius may be definitely recognized.
The simplest and on the whole most frequent type of musical
sentence or period consists of eight measures, subdivided into
two balancing phrases of four measures[51] each—the compo-
nent parts plainly indicated by various cadences and endings
soon to be explained. These four-measure phrases are often,
though not invariably, still further subdivided into two sections