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. It is true, nevertheless, not only that the fugue form makes the severest demands on the attention and intelligence of the listener, but also that, because of its ecclesiastical origin and polyphonic style, it is incapable of the kind of highly personal, secular expression that it was in the spirit of the seventeenth century to demand. The prototypes of secular expression are the popular dance and song, and as soon as learned musicians had discovered means to give to dance and song movements the completeness, breadth, and organic coherence requisite to large beauty, they began to turn their attention away from the austere if noble contrapuntal forms, and to base their art on more popular models. The result was that even in the age of Bach the suite of dance and song movements began to be cultivated almost as sedulously as the fugue, and Bach himself wrote suites which in their way are quite as good as his more polyphonic works. The second great phase in the application to pure music of the principles of metrical and harmonic design is represented by the Suite. As practiced by Bach, the suite is a series of dances and songs, written in a style partly polyphonic and partly monodic (that is, consisting of a single melody with subsidiary accompaniment). His introductory movements, allemandes in the French suites, preludes in the English, are stately or energetic contrapuntal pieces, intended to commence the suite with an impression of dignity. They are followed by courantes, bourrées, sarabandes, minuets, airs, and gavottes, all more or less definitely rhythmical and animated; and the concluding movement is generally a rollicking gigue. These suites of Bach may be considered perfect models of the form.