The sonata in F major and that in A major were written the following year, and are of strikingly different character, both speaking of the Mozart whose playing was long remembered for its quality of heart-melting tenderness. Unlike the first movement of the A minor sonata, the first movement of the F major is full of a variety of themes and motives. It is rather lyrical in character. The first theme has a song-like nature; and a beautiful measure or two of folk-song melody makes itself heard in the transition to the second theme, which is again lyrical. The development section opens with still another melody. There is an oft-repeated shifting from high register to low. The whole is wrapped in a veil of poetry. The slow middle movement is unexcelled among all slow movements for purity of style, for perfection of form, for refinement, but also tenderness of sentiment; and the last movement flows like a brook through Rondo Field. One cannot choose one movement from the others as being more beautiful either in spirit or workmanship; and the three together compose one of the flawless sonatas of pianoforte literature.
The more familiar sonata in A major is more irregular. It has, by the way, no movement in the triplex form. The first is an air and variations. It has long been a favorite with amateur and connoisseur alike. The naïve beauty of the air is irresistible. The variations throw many traits of Mozart’s style into prominence, particularly in the first and fifth, his love of entwining his harmonies, so to speak, with shadows and passing notes. The scoring of the fourth is wonderfully beautiful. The sixth is perhaps unworthy to follow the fifth. After the almost inevitable monotony of the variation form, it is perhaps to be regretted that the second movement, a minuet, continues the key of the first. The movement itself is of great charm. The trio is happily in D major. One would be glad to have it in any key, so exquisite and perfect is its beauty. The last movement, a rondo alla Turca, takes up the key of A again. That it is in minor, not major, hardly suffices to break the monotony of tonality which may threaten the interest of the sonata as a whole. The rondo is engagingly jocund, but more ordinary than Mozart is elsewhere likely to allow himself to be.
Two later sonatas have a more serious allure than these earlier ones. That in C minor (K. 457), composed in 1784, is commonly considered his greatest sonata. Why such a distinction should be insisted upon, it is difficult to see. The C minor sonata is more weighty than the others, but is it for that reason greater? Must music to be great, hint of the tragic struggles of the soul? Such is the merit often ascribed to this sonata, as if there were no true greatness in a smile. Without setting up a standard of the great and the trivial in music, we may grant that the work has a compelling force. Let us not liken it to Beethoven. It still has the charm of which only Mozart was the master, that charm which remains one of the intangible, inexplicable things in music.
A sonata in F major (K. 533) was composed in 1788. The whole work is characterized by a possibly too prominent contrapuntal ingenuity. There is besides a boldness in harmonies, especially in the slow movement, which makes one wonder into what strange lands Mozart strayed when he sat improvising at the keyboard.
The sonatas as a whole rest, as we have said, upon a harmonic foundation which is relatively simple. The great Fantasia in C minor differs from them in this regard more than in any other. If, as Otto Jahn suggested in his ‘Life of Mozart,’ this fantasia may offer us some suggestion of what Mozart’s improvisations were like, we may be sure that such outpourings wandered into harmonies rich and strange.
The fantasia was composed in 1785, the year after the C minor sonata, to which it was at one time thought to have been intended as an introductory movement. An earlier fantasia in D minor is fragmentary. It ends abruptly and leaves an impression of incompleteness on the mind of the listener. The C minor fantasia is without definite form, but the return of the opening motive at the end gives it a logical balance. It divides itself into five or six sections. The tempo is not very fast in any one of them, but there is an uneasy current of unrest running under the whole.
It would be foolish to attempt an analysis of what may be its emotional content. It calls for no such analysis, but stands as another instance of the strange power Mozart’s music has to satisfy of itself alone. It must remain, like his other work, mysterious and of secret origin. Only one section is given a key-signature. The others are without harmonic limitation. Perhaps the opening section, and the brief part of it repeated at the end, are the most impressive. The motive out of which they are built is of unfathomable significance; their harmonies rise and fall as slowly and mysteriously as the tide. Of the quality of other more melodious sections, of the occasional charm and grace that here and there rise, as it were, on the wings of light; of the passionate harmonies that die away into silence before the slow opening motive returns inexorably, nothing can be said. There comes over it in memory the light that never was on land or sea. It is a poet’s dream.
III
We have now to consider the pianoforte concertos which as a whole may be taken to be the finest of his works for the instrument. They were written primarily for his own use, seventeen of them in Vienna between 1783 and 1786, some earlier, however, and a few later. They are concertos in the modern sense, not like the concertos of Sebastian Bach. In the latter we find the clavier treated in much the same style as the orchestra or the tutti, as it was, and still is, generally called. In the Mozart concertos, on the other hand, the solo instrument is given a rôle which will show off to the best its peculiar qualities. The Vivaldi form of concerto, such as Bach used, was a modified rondo; that is to say, there was one chief subject, usually announced at the beginning by the tutti. This subject properly belonged to the tutti, and the solo instrument was given various episodes of contrasting material, between which the orchestra usually was introduced with ritornelles based upon the chief subject. The whole was a sort of dialogue between soloist and orchestra.
The form of the concerto which Mozart used was clearly as follows: an expanded triplex form for the first movement, a slow movement in song form, and a rondo of the French type for the finale. Moreover, he used the solo instrument not only alone, but with the orchestra; in such cases writing a brilliant sort of fioritura for it, which added a special and distinct color to the ensemble. Such a form of concerto was apparently first employed by Christian Bach in London. From him Mozart learned the use of it. He was not, therefore, as has often been stated, the true ‘father’ of the modern concerto. Nevertheless it was he who first used the form with enduring success, and it may be considered as his special contribution to the standard musical forms.