[Music: score] [Illustration: FIGURE X. EXAMPLES OF AUGMENTATION AND DIMINUTION.]
It will be well worth the reader’s while to play through the entire fugues cited, noting the marvelous skill and subtlety with which Bach weaves his fabric.
In augmentation and diminution the original accents of the motif are for the most part retained--it is only the durations that are altered. More transformative still, therefore, are those devices which actually shift the accents of the motif, its most salient and identifying features. The most important of these, which we may call “shifted rhythm,” is seldom found in Bach; for its frequent and exhaustive application we must look to Mozart, Beethoven, and Brahms. As its name indicates, “shifted rhythm” consists in bodily shifting or transposing the motif in such a manner that its heavy beats become light, and its light ones heavy. In order to complete our account of the chief means of exploiting motifs, a few examples of shifted rhythm may find place here, even though they are not taken from Bach.
[Music: score] [Illustration: FIGURE XI. EXAMPLES OF SHIFTED RHYTHM. From the Minuet of MOZART’S String Quartet in C-Major.]
[Music: score] [Illustration: From the First Movement of BEETHOVEN’S Eighth Symphony.]
[Music: score] [Illustration: From the First Movement of BRAHMS’S Second Symphony.]
The foregoing discussion and examples will serve to give a slight idea of the wonderfully varied means of manipulating short motifs or musical subjects which composers derive from the peculiarities of metrical and harmonic organization. These means were utilized by Bach in the fugue with tireless industry and inexhaustible imagination. The fugue became in his hands the most perfect in its orderly complexity of all the forms of pure music; for sheer intellectual interest of a highly abstract kind his fugues have never been surpassed. Nor are they, as those unfamiliar with their intricacies are apt to suppose, devoid of emotional expression. The profundity, poignancy, and variety of the feeling they express are as marvelous as their consummate beauty of structure. They voice every mood, from the most earnest and impassioned gravity to the lightest banter. They are the first great independent monuments of pure music; and wherever future musicians may wander in the quest of new forms and new potencies of expression, Bach’s fugues will always stand magnificent on the horizon, marking the unassailable eastern heights from which pilgrimage was begun.