Of this perfect masterpiece we have already spoken. It is well to recall attention to the fact, however, that the first and last movements are of about equal length and significance. Both are in rapid tempo and of careful and more or less close-knit workmanship; and both are in the key of F major. The movement between them is in a different key (D minor) and of slow tempo and wholly contrasting character. Here, then, as regards the number and grouping of movements in the sonata, we have in the work of the father, the model for the son Emanuel. For so far as Emanuel Bach contributed at all to the external structure of the pianoforte sonata, it was by adhering consistently to this three-movement type which was later adopted by Haydn, Mozart, and, to a great extent, Beethoven. His consistency in this regard is indeed well worth noticing. For between the years 1740 and 1786, when he composed and published his numerous sets of sonatas, there was much variety of procedure among musicians. Bach, however, rarely varied; and this, together with the models his father left, justifies us in calling the sonata in three movements distinctly the German type of this period. Meanwhile composers who were more in the current of Italian music fought shy of committing themselves to a fixed grouping of movements. Italian instrumental music was taking a tremendous swing towards melody and lightness. This was especially influential in shaping the triplex form of movement; but was also affecting the general grouping. Padre Martini (1706-84) of Bologna alone adhered to a regular, or nearly regular, number and sequence of movements in harpsichord sonatas. His twelve harpsichord sonatas, published in Amsterdam in 1742, but written some years earlier, seem strangely out of place in their surroundings. To begin with, even at this late date they are written either for organ or for harpsichord. This alone prepares us for the general contrapuntal style of them all. Then, though named sonatas, they are far more nearly suites. Each is composed of five movements. The first is regularly in sonorous prelude style, suitable to the organ. The second is regularly an allegro in fugal style, the third usually an adagio. The fourth and fifth are in most cases dances,--gavottes, courantes or gigues, with sometimes an aria or a theme and variations. All the movements in one sonata are in the same key. Only one feature resembles those of the growing Italian harpsichord sonata: the generally light dance character of the last or the last two movements. For what is very noticeable in the sonatas of E. Bach is that the last movements, though cheerful in character, are usually of equal musical significance with the first.