great Corelli. His sonatas only appeared after those of his
illustrious pupil, yet may have been composed before. Of the twelve in
Op. 5, most have many short movements; some, indeed, are so short as
to be scarcely deserving of the name.

By the time of Arcangelo Corelli, who, as mentioned, published his
first work (Op. 1, twelve sonatas for two violins and a bass) in 1683,
sonatas answered to the definition given by Mattheson in his _Das neu
eröffnete Orchester_ (1713), in which they are said to consist of
alternate Adagio and Allegro. J.G. Walther, again, in his dictionary
of music,[1] which appeared at Leipzig in 1732, describes a sonata as
a "grave artistic composition for instruments, especially violins."
The idea of grouping movements was already in vogue in the sixteenth
century. Morley in his _Plain and Easy Introduction to Practical
Music_, printed in 1597, speaks of the desirableness of _alternating_
Pavans and Galliards, the one being "a kind of staid musick ordained
for grave dancing," and the other "a lighter and more stirring kind of
dancing." Contrast was obtained, too, not only by difference in the
character, but also, in the measure of the music; the former was in
common, the latter in triple time.

With regard to the grouping of movements, Corelli's sonatas show
several varieties. The usual number, however, was four, and the order
generally--slow, fast, slow, fast. Among the forty-eight (Op. 1, 2, 3,
and 4, published 1685, 1690, 1694, and 1700 respectively) we find the
majority in four movements, in the order given above[2]; of the twelve
in Op. 3, no less than eleven have four movements, but--

No. 1 (in F) has Grave, Allegro, Vivace, Allegro.
No. 6 (in G), Vivace, Grave, Allegro, Allegro.