By far the greater part of these many pieces are independent of each other. Except in a few cases where Scarlatti, probably in his youth, followed the model of his father’s toccatas, he keeps quite clear of the suite cycle. The pieces have been called sonatas, but they are not for the most part in the form called the sonata form. This form (which is the form in which one piece or movement may be cast and is not to be confused with the sequence or arrangement of movements in the classical sonata) is, as we shall later have ample opportunity to observe, a tri-partite or ternary form; whereas the so-called sonatas of Scarlatti are in the two-part or binary form, which is, as we have seen, the form of the separate dance movements in the suite. Each ‘sonata’ is, like the dance movements, divided into two sections, usually of about equal length, both of which are to be repeated in their turn. In general, too, the harmonic plan is the same or nearly the same as that which underlies the suite movement, the first section modulating from tonic to dominant, the second back from dominant to tonic. But within these limits Scarlatti allows himself great freedom of modulation. It is, in fact, this harmonic expansion within the binary form which makes one pause to give Scarlatti an important place in the development of the sonata form proper.
The harmonic variety of the Scarlatti sonatas is closely related to the virtuosity of their composer. He spins a piece out of, usually, but not always, two or three striking figures, by repeating them over and over again in different places of the scale or in different keys. His very evident fondness for technical formulæ is thus gratified and the piece is saved from monotony by its shifting harmonies.
A favorite and simple shift is from major to minor. This he employs very frequently. For example, in a sonata in G major, No. 2 of the Breitkopf and Härtel collection of twenty sonatas[13] measures 13, 14, 15, and 16, in D major, are repeated immediately in A major. In 20, 21, 22, and 23, the same style of figure and rhythm appears in D major and is at once answered in D minor. Toward the end of the second part of the piece the process is duplicated in the tonic key. In the following sonata at the top of page seven occurs another similar instance. It is one of the most frequent of his mannerisms.
The repetition of favorite figures is by no means always accompanied by a change of key. The two-measure phrase beginning in the fifteenth measure of the third sonata is repeated three times note for note; a few measures later another figure is treated in the same fashion; and in yet a third place, all in the first section of this sonata, the trick is turned again. Indeed, there are very few of Scarlatti’s sonatas in which he does not play with his figures in this manner.
We have said that often he varies his key when thus repeating himself, and that such variety saves from monotony. But it must be added that even where there is no change of key he escapes being tedious to the listener. The reason must be sought in the sprightly nature of the figures he chooses, and in the extremely rapid speed at which they are intended to fly before our ears. He is oftenest a dazzling virtuoso whose music appeals to our bump of wonder, and, when well played, leaves us breathless and excited.
The pieces are for the most part extremely difficult; and this, together with his ever-present reiteration of special harpsichord figures, may well incline us to look upon them as fledgling études. The thirty which Scarlatti himself chose to publish he called esercizii, or exercises. We may not take the title too literally, bearing in mind that Bach’s ‘Well-Tempered Clavichord’ was intended for practice, as were many of Kuhnau’s suites. But that Scarlatti’s sonatas are almost invariably built up upon a few striking, difficult and oft-repeated figures, makes their possible use as technical practice pieces far more evident than it is in the ‘Well-Tempered Clavichord’ or even the ‘Inventions’ of Bach. He undoubtedly offers the player enormous opportunity to exercise his arms and his fingers in the production of brilliant, astonishing effects.
Of these effects two will always be associated with his name: the one obtained by the crossing of the hands, the other by the rapid repetition of one note. Both devices will be found freely used in the works of his father, and it is absurd to suppose that the son invented them. Yet it is hardly an exaggeration to say that he made more use of them than any man down to the time of Liszt. The crossing of the hands is not employed to interweave two qualities of sound, as it oftenest is in music for the organ or for the German and French harpsichords which have two or more manuals that work independently of each other. The Italian harpsichords had but one bank of keys, and Scarlatti’s crossing of the hands, if it be not intended merely for display, succeeds in making notes wide apart sound relatively simultaneous, and thus produces qualities of resonance which hitherto had rested silent in the instrument.
It has been suggested that the device of repeated notes was borrowed from the mandolin, on which, as is well known, a cantabile is approximated by rapid repetition of the notes of the melody. Scarlatti, however, rarely employs it to sustain the various notes of his tune. In his sonatas it is usually, if not intentionally, effective rhythmically; as it is, unfailingly, in more modern pianoforte music. On the harpsichord, moreover, as on the pianoforte, it can make a string twang with a sort of barbaric sound that still has the power to stir us as shrieking pipes and whistles stirred our savage ancestors.
Still another mannerism of his technique or style is the wide leap of many of his figures. A plunge from high to low notes was much practised in contemporary violin music and was considered very effective, and probably suggested a similar effect upon the harpsichord. Into this matter again Scarlatti may well have been initiated by his father, by whom it was not left untried. In the son’s sonatas it succeeds in extending the range of sonority of the harpsichord, and thus points unmistakably to developments in the true pianoforte style.
It is, in fact, by this extension of figures, by sudden leaps, by crossing of hands, that Scarlatti frees harpsichord music from all trace of slavery to the conjunct style of organ music; and he may therefore be judged the founder of the brilliant free style which reached its extreme development in the music of Liszt. Though we may not fail to mention occasionally his indebtedness to his father and to instrumental music of his time, we cannot deny that he is a great inventor, the creator of a new art. He was admitted by composers of his day to have not only wonderful hands, but a wonderful fecundity of invention.