Beethoven’s Gradual Development.—But Beethoven did not arrive at this result in an instant. It is true that, even in his early works, a distinction of style is shown which removes them from a mere imitation, but, as has been shown, he began practically at the point where Haydn and Mozart left off, with compositions which can hardly be placed on a higher level than theirs; and, in the course of a life full of strenuous experiences, he gradually unfolded the resources which he had received from his predecessors, until he made them adequate to give vent to the mighty ideas which welled from his soul. Thus we find in his works a period in which form is rigidly observed; and we pass thence through an era of expansion, during which form becomes more elastic, through the added requirements placed upon it, until the thought and emotion become so paramount that the formal lines have entirely disappeared, and are only to be traced by careful analysis.

Beethoven and the Orchestra.—As the great exponent of instrumental music, Beethoven found the orchestra his best and fullest vehicle of expression. So his massive mind, grasping with ease the effects of manifold combinations of instruments, was able to mould his thoughts into terms of tone color in which each instrument should be employed to bring out the exact shade of feeling required. So the orchestra becomes with him a great individual instrument, responding to the slightest change of mood.

Use of the Piano.—But as a preparation for such orchestral work, Beethoven realized the value of the pianoforte. Attaining a marvelous degree of virtuosity in the use of the keyboard at an early age, he later found this of the greatest advantage in working out his ideas, and, further, in actually trying their effects upon auditors. Thus we find in his first pianoforte sonatas effects which appeared much later in the greater elaboration of his symphonies; thus also is shown the necessary imperfection of any division of his works into distinct periods, since his pianoforte style was so greatly in advance of his orchestral.

Improvement in the Piano.—In this connection, it is important to note that Beethoven’s resources were greatly increased by the improvements which had been made in piano manufacture. The demand for instruments, created by the growing popularity of the pianoforte, stimulated manufacturers to redoubled energy in perfecting them; and, conversely, the added resources thus developed were an instigation to composers to test their abilities in the invention of new effects. Thus Beethoven was placed in command of a piano of much greater power than Mozart’s; and the work of technicians, like Clementi, for whom he had great respect, was already hinting at new and marvelous possibilities.

Added Sonority and Sustaining Power.—This strength of construction resulted in greater sonority. Hence we find full chord progressions and rich floods of tone in Beethoven’s works, in place of the dainty harmonic accompaniment of former writers. Moreover, the increase in sustaining force, enhanced by the use of the pedal, made possible a sustained legato tone for singing passages, which had formerly to be merely hinted at through shakes and other embellishments. A consequent tone variety made it possible to emphasize a single voice in this way, while the accompanying harmonies could be kept well in the background. Again, this range of tone proved an incentive for long crescendos, from the softest suspicion of sound to an overwhelming tonal climax.

Increased Compass.—The added range which the keyboard developed also enhanced such effects, by the chance for brilliancy in the treble, and for profundity in the bass; moreover, Beethoven was quick to make use of the variety of effects caused by playing in the different registers; sometimes suggesting in this way the contrast in the orchestra between different groups of instruments, such as the strings and woodwind.

Structure of Beethoven’s Sonatas.—With such resources at his command, Beethoven was able to give a fuller scope to the Sonata than was formerly possible, filling out each movement, and perfecting it for the expression of an integral part of the general idea, and finally placing it in its proper relationship to the whole. The Sonata Form, as settled by Haydn, was made the point of departure, serving almost invariably as the basis of the first movement, and frequently, in shortened form, for the second, generally slow, movement. For the third movement, Beethoven at first employed the Minuet, following the custom in the symphonies of Haydn and Mozart; but later this was generally omitted in the pianoforte sonatas, while in the symphonies its time was quickened into that of the dainty, sparkling Scherzo. For the finale, the Rondo form was most frequent; though, in order to give a fuller compass to the thought, a combination of the Rondo and Sonata forms was invented by Beethoven, and used even in his first sonatas. The Rondo form also appeared occasionally in the slow movement. Add that other forms, notably that of the Variation, sometimes supplanted one or the other of these, and we have the structure generally followed by Beethoven.

Unity of Conception.—All these movements were associated in an organic unity of conception which made one grow out of another with perfect naturalness. Sometimes, indeed, as in opus 27, a continuity of performance was indicated; always, however, the feeling of dependence of one movement upon another is present; so that the criticism made upon Haydn’s symphonies, that a movement of one could be interchanged with a similar movement of any other without perceptible difference, could never be made with regard to Beethoven’s works.

Key Relationship.—In key relationship, Beethoven struck out from stereotyped paths, frequently using contrasting keys related to the third of the initial chord; thus a movement or passage in C major might be followed by any key related to E, the third of the chord of C, such as E or A major or minor. The original key was most widely departed from in the slow movement, where the beauty of contrast was exceptionally noticeable.

Number of Movements.—The number of movements which he adopted was at first four, but this afterwards varied considerably, two or three movements prevailing; while in the fantasie-sonatas, and especially in the last five sonatas, an indefinite number of movements, some of them very short, appeared. He explained this discrepancy on the ground that he adapted the number of movements to his thought; and when he felt that he had given complete expression to this, the sonata was brought to a close.