place in musical dictionaries. Yet these variations are of great
moment in the history of development. And this for a double reason.
First, many of the works must have been known to E. Bach, and yet he
seems to have remained, up to the last, faithful to the three-movement
plan. One or two of his sonatas have only two movements, none,
however, has four. Secondly, the experiment of extending the number to
more than three, practically passed unheeded by Dussek, Clementi,
Mozart,[31] Haydn,[32] and by all the composers of importance until
Beethoven. The last-named commenced with sonatas in four movements;
but, as will be seen in a later chapter, he afterwards became partial
to the scheme of three movements.

Let us now consider, and quite briefly, movements in binary form;
again, in this matter, some instructive facts will be gathered from
the works of Bach's contemporaries. As in Scarlatti, so here we find
the first of the two sections into which such a movement is divided,
ending in one case[33] in the tonic, but, as a rule, in the dominant.
There is, however, an instance of the close in the under-dominant
(Müthel, No. 2 of the Sonatas of 1780), and in E. Bach, in the
relative minor of the under-dominant (Sonatas of 1780, No. 3, Finale).
In a minor key, the first section closed either in the key of the
relative major, or that of the dominant minor[34]--much more
frequently the former.

Now, in proportion as the second part of the first section grew more
definite, so also did the approach to it. Everyone knows the pause so
frequently to be found in Haydn and Mozart, on the dominant of the
dominant, _i.e._ if the key of the piece were C--

[Music illustration]