We are to study in this work only the organist Bach. Since M. André Pirro has so conscientiously analyzed the specific work of the master, I have to concern myself only with his technique as a virtuoso.
Bach played the clavecin in the following manner: "The five fingers so curved that their tips fell perpendicularly upon the keys, over which they formed a parallel line, ever ready to obey. The finger was not raised vertically upon leaving the key, but was drawn back, almost gliding toward the palm of the hand; in the passage from one key to another this sliding motion seemed to impart to the succeeding finger exactly the same degree of pressure, thereby ensuring perfect equality; a touch neither 'heavy,' nor yet dry (sec)." This we learn from Philipp Emanuel.
Bach's hand was comparatively small; the movement of his fingers was hardly perceptible, extending only to the first joints. His hand preserved its rounded shape even in the most difficult passages, Forkel tells us; the fingers were raised very little above the keyboard, hardly more than in a trill; as soon as a finger was no longer needed, he took pains to replace it in its normal position.... "The other parts of his body took no part in the performance, contrary to the habit of many people whose hands are incapable of sufficient agility."
To-day we no longer play the harpsichord; and the pianoforte, which has happily replaced it, makes demands never dreamed of in those days.
As to the character of organ touch, no change has taken place in two centuries. Possibly at the time of Bach the keys of the pedals were slightly different from those of our day; undoubtedly in his youth he made much less use of the heel than of the toe, since the pedal-keys were extremely short. But he soon recognized the necessity of perfecting the bass keyboard of the organ both by extending its compass and by lengthening the pedal-keys to their present dimensions.
He played with the body inclined slightly forward, and motionless; with an admirable sense of rhythm, with an absolutely perfect polyphonic ensemble, with extraordinary clearness, avoiding extremely rapid tempi; in short, master of himself, and, so to speak, of the beat, producing an effect of incomparable grandeur.
His contemporaries speak enthusiastically of his exquisite taste in the combination of registers, and of his manner of treating them, at once so unexpected and original.
Nothing could escape him which was related to his art, adds Forkel. He observed with the most minute attention the acoustic properties of the room where he was to play. On his visit to Berlin in 1747, he was conducted to the auditorium of the new opera house. He recognized at a glance the advantages and defects of this monumental edifice, in its relation to music. He was shown the grand foyer adjacent. Standing in the mezzanine gallery, he glanced up toward the ceiling and remarked immediately, without giving himself the trouble of further examination, that in it the architect had constructed "a work of great merit," perhaps unawares.
The foyer was in the form of a parallelogram; if a person standing in a corner of it, face toward the wall, spoke a few words, another person standing in the same position in the corner diagonally opposite could distinctly hear them, while the public, scattered here and there through the hall, would be unable to catch anything of this dialogue.
When distinguished strangers asked to hear Bach at the organ, at times other than during services, he usually selected some theme and amused himself by treating it in various ways, perhaps playing without interruption for over an hour. First he made use of the subject for a prelude and fugue, upon the foundation stops of the chief manual, thereafter deftly varying his registration through a series of episodes in two, three, or four parts. Then came a chorale, the melody of which was interrupted here and there by fragments of the original subject; and he finally concluded with a fugue for full organ,[2] in which "he contented himself with treating the subject either alone, or in combination with other themes derived from it."