ninth measure to C major, the Subdominant. This acceptance
of other tonal centres—distant a fifth from the main key-note—
doubtless arose from their simplicity and naturalness, and was
later sanctioned by acoustical law; the interval of a perfect fifth
having one of the simplest ratios (2-3), and being familiar to
people as the first overtone (after the octave) struck off by any
sounding body—such as a bell or an organ pipe. The Venetian
composers, notably Willaert, had also quite fully developed this
principle of Tonic, Dominant and Subdominant harmony in or-
der to give homogeneity to their antiphonal choruses. Even
to-day these tonal centres are still used; for they are elemental,
like the primitive colors of the spectroscope. But modulation,
in the modern sense of a free shifting of the centre of gravity
toany oneof the twelve semitones of our chromatic scale, was
not developed and accepted until after the acoustical reforms of
Rameau, and the system of tuning keyed instruments embodied
in that work called theWell-tempered Clavichordof Sebastian
Bach. Both these men published their discoveries about the year
1720.
[Footnote 25: In counting the measures of a phrase always con-
sider the firstcompletemeasure,—nevera partial measure—as
one.]
As we have just used the termmodal, and since many Folk-
songs in the old modes sound peculiar or even wrong (hence the
preposterous emendations of modern editors!) because our ears
can listen only in terms of the fixed major and minor scales, a
few words of explanation concerning the nature of the medieval
modes should here be given. Their essential peculiarity is the
freer relationship of tones and semitones than is found in the
definite pattern of our modern scales. It is of great importance
that the music-lover should train himself to think naturally in
these modes; for there has been a significant return to their
freedom and variety on the part of such modern composers as
Brahms, Tchaikowsky, Dvo[vr]ák, d’Indy, Debussy and others,
and some of their most individual effects are gained through
the introduction of modal types of expression. The following
modes are those most commonly employed in the formation of
Folk-songs.
[Music: DORIAN]
[Music: PHRYGIAN]