The knowledge of music, then, is the knowledge of the facts, and the facts are, as we saw, the alphabet of music, the twelve artificial semi-tones of the tempered scale. If a musician knows these and knows those combinations of them which are called intervals--as the combinations of letters are called words--he knows what the man knows who knows the letters of the alphabet and has a vocabulary of words. He may know them by sight, by sound, or by sight and sound. If only by sight he is in the position of a man who can read and write but not speak the words of a foreign language; if only by sound he is in the position of a man who can speak the words of a foreign language and understand them when spoken but cannot read or write them. The reader can make this analogy more precise by subdivisions which I shall not bother to make here. I will merely point out that the ordinary auditor, the music-lover who is no musician, knows the facts by sound only and may so know them with greater or less precision and depth of impression. That he should not know them by sight is immaterial to his understanding what he hears, although it prevents his communicating what he hears to anyone else. He is therefore technically equipped to hear but not to compose music. Such knowledge may extend beyond the knowledge of the vocabulary of words or chords to those more complicated combinations which have also died and become facts--sentences, idioms, ideas; or, in music, sequences, harmonies, melodies. All this knowledge represents so much dead life which can be incorporated into a page of music as it can be incorporated into a page of prose. When sentences, idioms and ideas (or sequences, harmonies and melodies) have been used over and over again so frequently as to have become immediately recognizable they cease to have meaning; because, as I pointed out at the beginning of this chapter, having been used so often in so many different contexts they have shrivelled to that residuum or abstraction which fits the lot. Having shed all individuality they shed all expression, and what was once life becomes knowledge. For example, what was a feeling in Wagner becomes merely a major ninth in Vincent d’Indy. When the music of Debussy was first heard it was an emotional experience. Presently the intellect abstracted an element which it found commonly in that experience, and that element was the whole-tone scale. Then everybody by using the whole-tone scale could write music which superficially sounded like Debussy’s; but such music had no meaning or life, it was dead music, mere knowledge. And Debussy’s music itself tended to become a perceptive and not an emotional experience. There is a universal tendency to this intellectual formalizing, stereotyping process which I have called knowledge or death; and contrasted with it everywhere is a complementary process, the process of creation or life. But the one is necessary to the other and all experience is the one becoming the other.