CHAPTER XVIII
FORMS OF COMPOSITION. THEORY AND LITERATURE
137. The Larger Forms in General.—The problem of method
or form in composition, especially for instruments, attracted increasing
attention throughout the 18th century. It was clearly
seen that no long and elaborate work can be intelligible unless
either divided into comparatively short sections, each relatively
complete in itself, or developed in such stages and by such orderly
processes that the mind can regard it as an organic whole. Several
notable forms were brought over from the preceding period
in a fair degree of advancement. These were either perfected
or greatly improved, so that about 1750 the way was open for
certain further steps that were reasonably final.
A complete and satisfactory classification of all the extended forms in use after 1700 is not possible, since some of them were variously construed by different writers, so that they overlapped. Any survey of them must consider two points, first, how far and how they are built up out of more or less distinct 'movements,' and second, what internal method of treatment is used within single movements.
Works in several separate movements are often called 'cyclical,' though
this term is better applied to a circling or recurrent treatment within a
movement, as in a rondo or in a stanza-song.
In all large works the division of the whole into movements
was common. Thus the opera and the oratorio were regularly
made up of distinct recitatives, arias, choruses, etc., the recitatives
usually serving as rather formless introductions to the
formal aria or chorus that followed. Thus the overture was regularly
split up into three or four sections, each with its own scheme
and subjects. Thus sets of dances were frequent, in which the
individual components were often so complete in themselves
that they could be used alone or recombined in other orders
without special inconvenience. In all these cases the total effect
