A Dictionary of Music and Musicians/Development
DEVELOPMENT. A word used in two somewhat different senses; on the one hand of a whole movement, in a sense analogous to its use with reference to an organism; and on the other of a subject or phrase, with reference to the manner in which its conspicuous features of rhythm or melody are employed by reiteration, variation, or any other devices which the genius or ingenuity of the composer suggests, with the object of showing the various elements of interest it contains.
The term is very apt and legitimate when used in the above senses, which are in reality no more than the converse of one another; for the development of a movement is rightly the development of the ideas contained in its subjects; otherwise in instrumental music neither purpose nor unity of design could be perceived. It must however be borne in mind that the mere statement of a transformed version of a subject is not development. A thing is not necessarily developed when it is merely changed, but it is so generally when the progressive steps between the original and its final condition can be clearly followed.
The most perfect types of development are to be found in Beethoven's works, with whom not seldom the greater part of a movement is the constant unfolding and opening out of all the latent possibilities of some simple rhythmic figure. It is impossible to give examples, owing to the space they would require; but reference may be made to the first movement of the Symphony in C minor; the Scherzo of the 9th Symphony; the Allegro con brio of the Sonata in C minor, opus 111; the last movement of the Sonata in F, opus 10, no. 2 ; and the last movement of the Sonata in A, opus 101.