ental--from twice to five
times as often per second, sounding the octave above, the fifth of that
octave, the second octave, the major third of that octave, etc. So
important is it to the individual musical quality of tone, to secure the
cooperation of overtones, that in certain large open organ pipes, which
are deficient in these, extra pipes of higher pitch and corresponding
with the overtones of the fundamental note, are added and joined to the
register. Overtones without the fundamental can be obtained on stringed
instruments by stopping one of the strings and then touching it lightly
at other points. The soft, sweet, ethereal character of the harmonics
produced in this manner on a violin conveys some idea of the manner in
which the many overtones of a note give it its distinctive quality.

In a way the overtones may be said to echo the fundamental, but the
ear receives fundamental and overtones blended as one tone of a
certain timbre. What that timbre is, is determined by the shape of
the resonating cavity or cavities, the shape of which in turn is
determined by the shape of the instrument, and in different voices by
infinitesimal differences in the shape of various parts of the vocal
tract. All instruments of a kind are made more or less on the same
pattern and vary but little in shape. For this reason we have the
distinct violin, horn, clarinet or pianoforte timbre, and so on down
the list, but I repeat here that there are not such minute and
individual differences between instruments of the same kind as there
are between voices of the same range, because there are no such
minute and individual structural differences in instruments as in the
vocal organs of individuals--differences that each individual can
multiply _ad infinitum_ by the subtle and delicate play of muscles
acting in response to mental suggestion, art sense, inspiration,
temperament, psychic impulse, or by whatever cognate term one may
choose to call it.

There is little or nothing of psychology in Mackenzie's book, and yet,
like other writers on voice-production, he appears now and then to be
groping for it. Thus, when he speaks of the fundamental tone being
reinforced by its overtones--by a number of secondary sounds higher in
pitch and fainter in intensity--he adds very beautifully that every
resonance-cavity has what may be called its elective affinity, or one
particular note, to the vibrations of which it responds sympathetically
like a love