Perhaps the only great composers who escaped the direct influence of Bach are Gluck and Berlioz. Even Gluck reproduced in every detail of harmony and figure the first twelve bars of the Gigue of Bach's B flat Clavier-Partita in the aria "Je t'implore et je tremble" in Iphigénie en Tauride. But plagiarism, however unconscious, is a very different thing from that profound indebtedness which makes a great man attain his truest originality; and Gluck's training practically deprived him of Bach's direct influence, useful as that would have been to the attainment of his aims in harmonic and choral expression. The indirect influence no one could escape, for whatever in modern music is not traceable to Sebastian Bach is traceable to his sons, who were encouraged by their father in the cultivation of those infant art-forms which were so soon to dazzle the world into the belief that his own work was obsolete.
Bach's place in music is thus far higher than that of a reformer, or even of an inventor of new forms. He is a spectator of all musical time and existence, to whom it is not of the smallest importance whether a thing be new or old, so long as it is true. It is doubtful whether even the forms most peculiar to him (such as the arpeggio-prelude) are of his invention. Yet he left no form as he found it, - not even that most conventional of all, the Da Capo Aria, which he did not outwardly alter in the least. On the other hand, with every form he touched he said the last word. All the material that could be assimilated into a mature art he vitalized in his own way, and he had no imitators. The language of music changed at his death, and his influence became all-pervading just because he was not the prophet of the new art, but an unbiassed seeker of truth. Whether so great a man becomes "progressive" or "reactionary" depends on the artistic resources of his time. He will always work at the kind of art that is most complete and consistent in all its aspects. The same spirit of truthfulness that makes Sebastian Bach hold himself aloof from the progressive art which he encourages in his sons, drives Beethoven to invent new forms and new means of expression with every work he writes.
Gluck abolished the Da Capo Aria, because it was unfit for dramatic music. Bach did not abolish it, because he did not intend to write dramatic music in the strict sense of the term. Mature musical art in Bach's time could not be dramatic, except in the loose sense in which the term may be applied to an epic poem. Dramatic expression, properly so called, can only be attained in music by the full development of resources that do not blend with those of Bach's art at all. Meanwhile there are many things unsuitable for the stage which are nevertheless valuable on purely musical grounds; and the Da Capo Aria was one. Bach developed it in a great variety of ways, while retaining even the minor details of what in other hands had long before become its conventional form; but the one thing he did not do was to abuse it according to time-honoured custom as the staple form for opera. For that he had too much dramatic insight. His treatment of other important art-forms is illustrated in the articles on Contrapuntal Forms; Concerto and Instrumentation. Here we may attempt to illustrate his methods by such forms and characteristics as cannot be classified under those headings.
1. The toccatas of Buxtehude and his predecessors show how Illustrations of Bach's method. an effective musical scheme may be suggested by running over the keyboard of an organ as if to try (toccare) the touch, then bursting out into sustained and full harmony, and at last settling down to a fugue. But before Bach no one seemed able to keep the fugue in motion long enough to make a convincing climax. Very soon it collapsed and the process of quasi-extemporization began again, to culminate in a new fugue which often gave the whole work a happy but deceptive suggestion of organic unity by being founded on an ingenious variation of the subject of the first fugue. But in Bach's hands the toccata becomes one of the noblest and most plastic of forms. The introductory runs may be disjointed and exaggerated to grotesqueness, until the gaps between them gradually fill out, and they build themselves up into grand piles of musical architecture, as in the organ toccata in C; or they may be worked out on an enormous scale in long and smooth canonic passages with a definite theme, as in the greatest of all toccatas, that in F for organ, which is most artistically followed by a fugue unusually quiet for its size.
In one instance, the toccata at the beginning of the E minor clavier-partita, the introductory runs, though retaining much of the extempore character from which the form derives its name, take shape in a highly organized and rounded-off group of contrasted themes. The fugue follows without change of time, and is developed in so leisurely a manner that it is fully as long as a normal fugue on a large scale by the time it reaches what sounds like its central episode. At this point some of the introductory matter quietly enters, and leads to a recapitulation of the whole introduction in the key now reached. The obvious sequel would be a counter-development of the fugue, at least as long as what has gone before, as in the clavier-toccata in C minor; but Bach does not choose to weary the hearer and weaken the impression of breadth he has already made here. Instead, he expands this restatement of the introduction, and makes its harmonies deliberately return to the fundamental key, and thus in an astonishingly short time the toccata is brought to a close with the utmost effect of climax and finality. The same grasp of all the possible meanings of an artistic device shows itself in his treatment of the other features of toccata form.
With his variety of proportion and flow he has no need to break off the fugue like earlier composers: but all the old devices by which the division into sections was managed are turned to account by him, and almost every toccata has its own scheme of contrasted movements, always based on the old natural idea of the growth of an organized music from a chaos of extemporization.