Arnold Schoenberg-ever since you sir, the composers need to explain what and why they do

Both Pictures taken from Amazon. 

As I stated, the day I finished the note of 'Did you say spectral?' I dig out Schoenberg's writing again.  He is one of the 'not quiet' one who writes and talks about his music a lot.  It was a trend at that time more and ever that composers must 'explain in writing' of what they are doing.  

Schoenberg is known for his polemical replies and if one ever reads his text book in Harmonielehre (Theory of Harmony) will be impressed by his craftsmanship.  It is a book to understand how he sees harmony and how eventually he reaches the point of finding twelve tone as the answer for music after Strauss' chromaticism.  It might not be an easy or clear reading, but defiantly a reading to understand him, as a composer, how he sees harmony works.  

In fact, when I was still teaching in Taiwan, I wish to make every single of my student to read Theory of Harmony, but one Harmony and Voice Leading is already quite a pain for them and had earn me some names I probably won't want to hear.

Schoenberg, Arnold 'Composition with Twelve Tones (1)' Style and Idea: Selected Writings of Arnold Schoenberg. Edited Stein, Leonard. translations Black, Leo. London: Faber & Faber, 1975.

Published in Style and Idea, 1950.  Notes for lecture (translated from German) at Princeton University, on March 6, 1934.

p. 214
To understand the very nature of creation one must acknowledge that here was no light before the Lord said: 'Let there be Light.'  And since there was not yet light, the Lord's omniscience embraced a vision of it which only His omnipotence could call forth (!...this reflects the general atmosphere around that time how arts and creativity were valued).

p. 215
.....
A creator has a vision of something which has not existed before this vision.
And a creator has the power to bring his vision to life, the power to realize it.
In fact, the concept of creator and creation should be formed in harmony with the Divine Model; inspiration and perfection, wish and fulfilment [sic], will and accomplishment coincide spontaneously and simultaneously.  In Divine Creation there were no details to be carried out later; 'There was Light' at once and in its ultimate perfection.

Alas, human creators, if they be granted a vision, must travel the long path between vision and accomplishment; a hard road where, driven out of Paradise, even geniuses must reap their harvest in the sweat of their brows.

Alas, it is one thing to envision in a creative instant of inspiration and it is another thing to materialize one's vision by painstakingly connecting details until they fuse into a kind of organism.

Alas, suppose it becomes an organism, a homunculus or a robot, and possesses some of the spontaneity of a vision; it remains yet another thing to organize this form so that it becomes a comprehensible message 'to whom it may concern'.

II
Form in the arts, and especially in music, aims primarily at comprehensibility.  The relaxation which a satisfied listener experiences when he can follow and idea, its development, and the reasons for such development is closely related, psychologically speaking, to a feeling of beauty.  Thus, artistic value demands comprehensibility, not only for intellectual, but also for emotional satisfaction.  However, the creator's idea has to be presented, whatever the mood he is impelled to evoke.

Composition with twelve tones has no other aim than comprehensibility.  In view of certain events in recent musical history, this might seem astonishing, for works written in this style have failed to gain understanding in spite of the new medium of organization.  Thus, should one forget that contemporaries are not final judges, but are generally overruled by history, one might consider this method doomed.  But, though it seems to increase the listener's difficulties, it compensates for this deficiency by penalizing the composer.  For composing thus does not become easier, but rather then times more difficult.  Only the better prepared composer can compose for the better-prepared music lover.

p. 216
III
The method of composing with twelve tones grew out of a necessity.

In the last hundred years, the concept of harmony has changed tremendously through the development of chromaticism.  The idea that one basic tone, the root, dominated the construction of chords and regulated their succession--the concept of tonality--had to develop first into the concept of extended tonality.  Very soon it became doubtful whether such a root still remained the centre to which every harmony and harmonic succession must be referred.  Furthermore, it became doubtful whether a tonic appearing at the beginning, at the end, or at any other point really had a constructive meaning.
.....
What distinguishes dissonances from consonances is not a greater or lesser degree of beauty, but a greater or lesser degree of comprehensibility.  In my Harmonielehre I presented the theory that dissonant tones appear later among the overtones, for which reason the ear is less intimately acquainted with them.  This phenomenon does not justify such sharply contradictory terms as concord and discord.

p. 217
The term emancipation of the dissonance refers to its comprehensibility, which is considered equivalent to the consonance's comprehensibility.  A style based on this premise treats dissonances like consonances and renounces a tonal centre.  By avoiding the establishment of a key modulation is excluded, since modulation means leaving an established tonality and establishing another tonality.
.....
Formerly the harmony had served not only as a source of beauty, but, more important, as a means of distinguishing the features of the form.  For  instance, only a consonance was considered suitable for an ending.  Establishing functions demanded different successions of harmonies than roving functions; a bridges, a transition, demanded other successions than a codetta; harmonic variation could be executed intelligently and logically only with due consideration of the fundamental meaning of the harmonies.

p.240
It is true that sound in my music changes with every turn of the idea--emotional, structural, or other.  It is furthermore true that such changes occur in a more rapid succession than usual, and I admit that it is more difficult to perceive them simultaneously.  ..... But it is not true that the other kind of sonority is foreign to my music.