Already in 1685, when Corelli's sonatas for strings appeared, the custom of decreasing the number of movements to three began to obtain, and a century later this custom was universal. The _allemande_, _overture_, or _preludio_ formed the first movement; the second consisted of the _sarabande_, the ancestor of our _adagio_; and the last part was generally a _gigue_. Even when the dance titles were no more used (the music having long outgrown its original purpose), the distinctive characteristics of these different movements were retained; the _sarabande_ rhythm was still adhered to for the _adagio_ (even by Haydn) and the triple time and rhythm of the _gigue_ were given to the last part. In addition to this, these three movements were often kept in one key. In his first sonatas Beethoven added a movement, generally a _minuet_, to this scheme; but returned to the three-movement structure later. His Op. 111 has only two movements, in a way returning to a still earlier general form of the sonata. Now, as has already been said, some of the earliest examples of instrumental music were mainly descriptive in character, that is to say, consisting of imitations of _things_, thus marking the most elementary stage of programme music. Little by little composers became more ambitious and began to attempt to give expression to the emotions by means of music; and at last, with Beethoven, "programme music" may be said, in one sense, to have reached its climax. For although it is not generally realized, he wrote every one of his sonatas with definite subjects, and, at one time, was on the point of publishing mottoes to them, in order to give the public a hint of what was in his mind when he wrote them. Analysis may be considered as the reducing of a musical composition to its various elements--harmony, rhythm, melody--and power of expression. Just as melody may be analyzed down to the motives and phrases of which it consists, so may the expressiveness of music be analyzed; and this latter study is most valuable, for it brings us to a closer understanding of the power of music as a language. For the sake of clearness we will group music as follows: 1. Dance forms. 2. Programme music. (Things. Feelings.) 3. The gathering together of dances in suites. 4. The beginnings of design. 5. The merging of the suite into the sonata. The dance tunes I need hardly quote; they consist of a mere play of sound to keep the dancers in step, for which purpose any more or less agreeable rhythmical succession of sounds will serve.