Vocal music, as we understand it, and as I have already
explained, began when the first tone could be given clearly;
that is to say, when the sound sentence had amalgamated into the
single musical tone. The pitch being sometimes F, sometimes G,
sudden emotion gives us the fifth, C or D, and the strongest
emotion the octave, F or G. Thus we have already the following
sounds in our first musical scale.

[G: f' g' c'' d'' f'']

We know how singers slur from one tone to another. It is a
fault that caused the fathers of harmony to prohibit what
are called hidden fifths in vocal music. The jump from G to
C in the above scale fragment would be slurred, for we must
remember that the intoning of clear individual sounds was
still a novelty to the savage. Now the distance from G to
C is too small to admit two tones such as the savage knew;
consequently, for the sake of uniformity, he would try to
put but one tone between, singing a mixture of A and B[flat],
which sound in time fell definitely to A, leaving the mystery
of the half-tone unsolved. This addition of the third would
thus fall in with the law of harmonics again. First we have the
keynote; next in importance comes the fifth; and last of all
the third. Thus again is the absence of the major seventh in
our primitive scale perfectly logical; we may search in vain
in our list of harmonics for the tone which forms that interval.

Now that we have traced the influence of passionate utterance
on music, it still remains for us to consider the influence