From Busoni's _Sketch of a New Esthetic of Music_

Since there has been some discussion of the "sound continuum" I would
like to add a contribution to our list from Ferruccio Busoni (my
teacher's teacher...) from his _Sketch of a new Esthetic of Music_,
first published in 1911:

"Fortunately, while busied with this essay, I received from America
direct and authentic intelligence which solves the problem in a
simple manner. I refer to an invention by Dr. Thaddues Cahill. He
has constructed a comprehensive apparatus which makes it possible to
transform an electric current into a fixed and mathematically exact
number of vibrations. As pitch depends on the number of vibrations,
and the apparatus may be "set" on any number desired, the infinite
gradation of the octave may be accomplished by merely moving a level
corresponding to the pointer of a quadrant.

"Only a long and careful series of experiments, and a continued
training of the ear, can render this unfamiliar material approachable
and plastic for the coming generation, and for Art.

"And what a vista of fair hopes and dreamlike fancies is thus opened
for them both! Who has not dreamt that he could float on air? and
firmly believed his dream to be reality? -- Let us take thought, how
music may be restored to its primitive, natural essence; let it be
pure invention and sentiment, in harmonies, in forms, in tone-colors
(for invention and sentiment are not the prerogative of melody
alone); let it follow the line of the rainbow and view with the
clouds in breaking sunbeams; *let Music be naught else than Nature
mirrored....*"

JP