The extent to which he mastered the difficulties of the keyboard in nearly all directions and his truly great inventiveness in pianistic effects, have filled his works with sheer technical difficulties which must ever task the skill of even the most remarkable virtuosi. He demands velocity and strength in the fingers, great endurance and power, flexibility of the wrist both in its usual up and down movement and in its movement from side to side, a sure free use of the arm. Skill in thirds and sixths, in octaves, in trills, double trills and even triple trills, in wide skips, in repeated notes, all this and more he demands of the player. It is ludicrous to think that certain contemporaries denied him distinction as a pianist, largely because he played according to no recognized method. As if any method of that day or even this could be expected to limit hands that could play, to say nothing of devise, such music as his!
He practically exhausted the resources of the pianoforte of his day. Of this he was aware, and his ear, growing ever finer in its appreciation of orchestral color, was at times tired of the limited tones of this single instrument. He is reported to have said of it that it is and remains an unsatisfactory instrument. At times he seems to have written for it as he would write for the orchestra. In the first movement of the ‘Waldstein’ sonata (opus 53) he actually wrote the names of instruments over phrases which they might be fancied playing. This one instance, together with passages which do not seem quite suited to the nature of the piano, must not mislead us, however, to judge the sonatas as orchestral rather than pianistic music.
Beethoven was thoroughly familiar with his piano. The instrument has been further improved since his day. Particularly the lower registers have been given greater sonority, and the instrument as a whole has gained much in sustaining power. Therefore it is inevitable that certain passages which he conceived upon the Broadwood or the Érard of 1820 or earlier are not wholly fitting to the modern piano. This is especially true of passages in the lower registers. The accompaniment to the noble second theme in the first movement of the sonata opus 57 is, for example, unquestionably thick. It is too low and muddy for the present-day piano. Many similar instances might be mentioned, most of which, however, prove only that pianos have changed. His frequent use of close accompaniment figures is perhaps intrinsically old-fashioned; but, on the other hand, wider figures would have been less sonorous on the piano he wrote for than those he used. It is, however, in such matters that Beethoven’s pianoforte music is, from one point of view, not entirely satisfactory to the pianist of today. If in other respects it is at times seemingly orchestral, if successive repetitions of the same phrase seem to tax the pianoforte too far, that does not take from it all as a whole the honor of being one of the greatest contributions to pure pianoforte literature.
It was natural that Beethoven’s conception of music as an art akin to poetry, conveying a more or less definite expression, should have great influence upon the forms in which he wrote. The sonata filled up enormously from his inspiration. To begin with, the triplex form took on more and more dramatic life. The development is to be noticed in several ways, some slower to make their appearance than others. Almost at once the contrasting natures of the first and second themes become apparent. Haydn, it will be remembered, often used but a variant of the first theme for the second, much as Emanuel Bach had done; but making his setting of the second theme far clearer. Mozart used distinctly different themes, but both were, as a rule, melodious, different in line but not in nature. On the other hand, the first three sonatas of Beethoven show a complete differentiation of the themes. The second and third are conspicuous and show a procedure in the matter of themes from which Beethoven rarely departed.
The first theme in the first movement of the sonata in A major, opus 2, No. 2, is positive in character, not lyric, not subtle, though in this case humorous. It is assertive and not likely to undergo radical change or development in the movement. That the first two measures are squarely on notes of the tonic chord should not be unobserved. The second theme is lyric, subtle, likely to change color and form as it passes through the various phases in store for it. The first and second themes of the next sonata may be characterized in almost the same words. And this is likely to be the case in nearly all movements in the triplex form which Beethoven will write. The first theme is likely to be assertive and strong, the second to offer a fundamental contrast in mood and style.
Both themes tend more and more to have a dramatic independence and significance. The movement grows, as it were, out of the conflict or the union of the two ideas which they express. A great vitality spreads into the connecting passages between them. These passages may develop from the nature of the first theme, as, for instance, in the sonatas opus 13, opus 31, No. 2, and opus 53, or they may present wholly new ideas often not less significant than the themes themselves, as in opus 10, No. 3, and in opus 57. Similarly the closing measures of the exposition take on a new meaning, as in the last movement of opus 27, No. 2, and opus 31, No. 2.
In the early sonatas, where Beethoven is somewhat preoccupied with the piano itself as a vehicle for the display of the pianist’s power, these intermediate measures have little musical merit. Such passages will be found in the first movements of opus 10, No. 3, and opus 22, both rather ostensibly virtuoso music. In the later sonatas such objective effectiveness is rare.
The development sections fill up with enormous vitality; and, finally, there grows a coda at the end of the movement in which in many cases the movement reaches its topmost height. In fact, Beethoven’s treatment of the coda makes of the triplex form something almost new. Where in classical form the movement might be expected to cease, in the sonatas of Beethoven it will be found often to flow on into a wholly fresh stanza, seeming at times the key or the fruition of the movement as a whole. The wonderfully beautiful and long coda at the end of the first movement of the sonata opus 81 is a superb case in point.
The remaining movements of the sonatas expanded under the same powerful imagination. Let one compare the variations which form the slow movement of opus 10, No. 2, with those in the slow movement of opus 106, or those which constitute the second and last movement of the last sonata. In these later variations we find something of the same change of the theme into various metaphors as that found in the Goldberg Variations of Bach. It is not so much an idea adorned as an idea expanded into countless new ideas. The variations written for the publisher Diabelli on a waltz theme are indeed exactly comparable to those of Bach.
To slow movements in song form or in triplex form he appended the codas in the nature of an epilogue which added so much to the first movements. The adagio of opus 10, No. 3, offers a fine example. Frequently the slow movement led without pause into the next, more frequently than in the sonatas of his predecessors.