EVOLUTION OF THEMATIC MATERIAL
MANY of men's most interesting discoveries and most useful inventions seem to be made when they are trying to find out something else. When any great problem is taken to pieces and discussed in sections there is always a danger of causing the inference that the particular aspect or phase under discussion was cultivated deliberately, with purpose set, and with full comprehension of definite objects; while, as a matter of fact, points of vantage, new products of combination, and new artistic methods seem to emerge rather than to be consciously sought for, and to be merely incidental to general efforts to advance and improve social or artistic conditions.
There is no explorer more hopelessly ignorant of the country ahead of him than the musician. Musicians who used sharps and flats to avoid disagreeable intervals in early choral music had no idea that their proceedings would lead to the extinction of their system of modes and the gradual emergence of the modern system of keys. The composers who thought that the basis of the form of their sonata movements was the distribution of