external spurs to creative activity.
And it asks in various quarters. It may ask merely the hint of
particular emotional moods conditioned by special circumstances; or it
may vie with the poet and the novelist in analysis of character. The
psychology, again, may pass into the illustration of incident, whether
partially realistic or purely imaginative, or into the illustration of
philosophical tenets, as in Strauss's version of Nietzsche's doctrines
in his _Also sprach Zarathustra_ or Scriabin's of theosophy in his
_Prometheus_. Or the composer may go directly to painting, whether
actual as in Rachmaninoff's symphonic poem on Boecklin's picture of 'The
island of the dead', or visionary as in Debussy's 'La cathedrale
engloutie'. There is indeed no end to such instances.

All this development of instrumental music into territories more or less
adjacent makes a very imposing show; and it is so markedly a product of
the last generation that we easily over-estimate the novelty of its
essential results. As I have said, instrumental music is more and more
asking for external spurs to creative activity; but this does not mean
that music as a whole is, so to speak, breaking loose from its moorings
and adventurously voyaging on to uncharted seas. What it means is,
simply, that, under the stress of modern culture, the barriers between
vocal and instrumental, dramatic and non-dramatic, music have been to a
great extent abolished.

We may consider music as normally involving three persons: the composer,
the performer, and the listener. Until the present generation, the role
of the listener was normally quite passive. All that he had to do was to
keep his ears open to the music, and further, when required, his ears
open to words and his eyes to dramatic presentation. The composer and
the performers did everything for him. But now they do not. The modern
composer urges that, just as vocal music demands from the listener a
separate knowledge of the words, so instrumental music may demand, as a
condition of full understanding, a separate knowledge of some verbally
expressible signification. The parallel no doubt holds well enough even
if we answer, as we certainly may, that in much vocal music the words
are so unimportant that it really does not musically matter if they are
unintelligible or inaudible. But this latter-day demand on the listener
is considerable. The listener to Strauss's _Don Quixote_, for example,
must, in order to app