Bach’s peculiar registration was based on his intimate knowledge of Organ building and of the properties of each individual stop. Very early in his career he made a point of giving to each part of the Organ the utterance best suited to its qualities, and this led him to seek unusual combinations of stops which otherwise would not have occurred to him. Nothing escaped his notice which had the slightest bearing on his art or promised to advance it. For instance, he made a point of observing the effect of large musical compositions in different surroundings. The practised ear, which enabled him to detect the slightest error in music even of the fullest and richest texture, and the art and rapidity with which he tuned his instrument, alike attest his intuitive skill and many-sidedness. When he was at Berlin in 1747 he was shown the new Opera House. He took in its good and bad qualities at a glance, whereas others had done so only after experience. He was shown the large adjoining Saloon and went up into the gallery that runs round it. Merely glancing at the roof he remarked, “The architect has secured a novel effect which, probably, neither himself nor any one else suspected.” The Saloon, in fact, is a parallelogram. If a person puts his face to the wall in one corner of it and whispers a few words, another person at the corner diagonally opposite can hear them distinctly, though to others between them the words are inaudible. The effect arises from the span of the arches in the roof, as Bach saw at a glance. These and similar observations suggested to him striking and unusual combinations of Organ stops. Bach brought the methods I have indicated to bear upon Church music, and they help to explain his extraordinarily dignified and inspired playing, which was at once so appropriate and filled the listener with deep awe and admiration. His profound knowledge of harmony, unfailing originality, freedom from a secular style, his complete command of the instrument, both manuals and pedals, whence flowed a generous stream of the richest and most abundant fancy, the infallible and swift judgment which allowed him always to select from the treasury of his mind precisely the musical ideas best suited to the occasion immediately before him, his intuitive grasp of every detail, and his power to make it serve his artistic ends—in a word, his transcendent genius brought the art of Organ playing to a degree of perfection which, till then, it had never attained and hardly will attain again. Quantz(133) has expressed the same opinion. “The admirable Johann Sebastian Bach,” he writes, “brought the art of Organ playing to its highest perfection. It is to be hoped that when he dies it will not be suffered to decline or be lost, as is to be feared from the small number of people who nowadays bestow pains upon it.”(134)