Most composers stick closely to their tonic key and modulate out of it with deliberation. In music that requires a large number of performers, and in a building, for instance a church, where the large volume of sound dies away slowly, such a habit shows good sense in the composer who wishes his work to produce the best possible effect. But in chamber or instrumental music it is not always a proof of wisdom, but rather of mental poverty. Bach saw clearly that the two styles demand different treatment. In his large choral compositions he bridles his exuberant fancy. In his instrumental works he lets himself go. As he never courted popularity, but always pursued his ideal, Bach had no reason to suppress the nobility of his inspirations, or to lower their standard for public consumption. Nor did he ever do so. Therefore every modulation in his instrumental work is a new thought, a constantly progressive creation in the plane of the chosen keys and those related to them. He holds fast to the essentials of harmony, but with every modulation introduces a new suggestion and glides so smoothly to the end of a piece that no creaking of machinery is perceptible; yet no single bar—I might almost say no part of a bar—is like another. Every modulation bears a strict relationship to the key from which it proceeds, and springs naturally from it. Bach ignored, or rather despised, the sudden sallies by which many composers seek to surprise their hearers. Even in his chromatic passages his progressions are so smooth and easy that we are hardly conscious of them, however extreme they may be. He makes us feel that he has not stepped outside the diatonic scale, so quick is he to seize upon the consonances common to dissonant systems and combine them to his sure purpose. [The Bach Statue at Eisenach] The Bach Statue at Eisenach CHAPTER VI. BACH THE COMPOSER (CONTINUED) Bach’s treatment of harmony and modulation powerfully influenced his melody. The strands of his harmony are really concurrent melodies. They flow easily and expressively, never engross the hearer’s attention, but divide his interest, as now one now the other becomes prominent. Even when they are noticeable they seem obscured by the melodic parts that accompany them—I say “seem obscured,” for if the hearer is sufficiently instructed to distinguish the several melodies in the ensemble he will discover them to be more clearly defined by their accompaniment.