(d) CHOPIN: Nocturne, Op. 53, No. 2.
Figure XV.
A melody in the right hand, accompanied by these broken chords in the left—this soon became the normal texture of music intended for the piano.
The first great merit of Chopin was that he carried to its logical extreme this system of counteracting the piano's defective sonority. The great advance made by him is shown even in the brief quotations of Figure XV. The Mozart example is rudimentary—the device at its lowest terms. In the Beethoven passage the chords are placed too low; they sound muddy, opaque, inelastic. In the Schubert passage the sonority is better, but the figures are so arranged as to be very difficult to play, on account of the wide jump the hand has to make at the middle of each measure. Chopin, on the other hand, avoids muddiness by clustering his harmony fairly high (about the region of middle C), at the same time gets a sufficient bass for his chords, which he is able to do by covering a great deal of ground in each figure, and in spite of the wide space traversed on the keyboard respects the comfort of the player by not requiring any sudden leaps. It is furthermore worthy of note that by introducing two tones foreign to the harmony (the fourth and the sixteenth) he gains a richness of sound lacking in the other examples. We get here, however, but the merest inkling of the inexhaustible ingenuity with which he manages this matter of "figuration," or the ornamental disintegration of chords. In order really to appreciate it we should have to examine those nocturnes, say, like the second, third, seventh, and eighth, in which with the left hand unaided he supplies a good firm bass and an intricate texture of accompaniment; we should have to study those pieces, such as the first, fifth, and eighth of the Études, opus 10, and the Prelude, opus 28, no. 23, in which it is the right hand that, racing back and forth over the keyboard, fills in the chinks of the harmony as a painter "stipples" an even tint with an infinite number of tiny brush-strokes; we should have to analyze in detail such a masterpiece as the Étude in A-flat major, opus 25, no. 1, in which it is both hands that weave together a diaphanous web of sound, while the outer fingers of one sing the tune, and those of the other the bass.[21]
Chopin's negative merit of minimizing the disadvantages of his instrument is, however, very intimately connected with a more positive skill in utilizing its peculiar advantages, in order to understand which we shall have to revert for a moment to our examination of the mechanism of the piano. The most characteristic feature of this mechanism—a feature so vital that it has been called the soul of the piano, and so unique that no other instrument except the harp presents a parallel to it—is the damper pedal, generally known by the inaccurate and misleading name of "the loud pedal." Its function is to raise all the dampers which control the vibrations of the strings, leaving them free to respond to any impulse they may receive. It thus secures two important results.
In the first place, it counteracts the non-sustainment of single tones by fusing a great many such individual tones, separately produced, into one impression. It will readily be seen, for instance, how indispensable is the pedal to the intended effect of the broken chords of Figure XV: only through its coöperation do they become worthy equivalents, in the piano idiom, of what the organ or voices would present in the form of sustained chords in long notes. Moreover, every tone sounded on the piano, with the pedal down, is reinforced, through what is known as sympathetic vibration, by many other tones not sounded by the hands at all. For, since every tone produced by a piano string is in reality, as proved by scientific analysis, by no means simple, but a complex of many elements known as "partial tones," and since any elastic body capable of producing a given tone will actually produce it, through sympathetic vibration, whenever the tone is already being otherwise sounded in its vicinity, it will readily be understood that all the partial tones set going by striking a piano key will, if the dampers are, by means of the pedal, kept from interfering, start into activity whatever strings are tuned to their respective pitches. Thus the pedal turns the entire body of strings into one vast Æolian harp, ready to take up, reëcho, and multiply the slightest breath of sound produced through the keyboard.
Some idea of the extraordinary enrichment of timbre or tone-quality which accrues to the piano through the sympathetic vibration made possible by the pedal may be gained by striking a single key, say middle C, first without, then with, the pedal. The first tone stands out hard and angular, like a leafless tree in a desert; the second is liquid, murmurous, palpitant, its outlines softened as a landscape is softened by a misty atmosphere. When a chord rather than a single key is struck, the effect is, of course, multiplied in direct proportion to the number of its constituent tones. The hard nucleus of the impression is clothed in a soft web of subordinate sounds, the result of sympathetic vibration. Suppose, for example, we play the chord of four whole notes in Figure XVI. If at the same time we free the strings by pressing the pedal, we shall summon from them an attendant train of ghostly "harmonics" for each of the four, represented in the figure by quarter-notes. These auxiliary tones, to be sure, will be exceedingly faint and individually indistinguishable, but they will nevertheless give to the impression that curious mellowness, depth, or liquidity (one calls vainly on the divers experiences of other senses to describe it) which is one of the fundamental charms of the piano tone.