The text of this chorale was, moreover, singularly appropriate to Bach's condition when he composed it, viewed as a lament amid the terrors of death, or as a declaration of readiness to appear before the throne of that God whose aid he invoked at the head of his compositions.[147]
This chorale has been called the "Swan-song."
In completing this study we must mention the chorale-accompaniments which Bach wrote to sustain the singing of the congregation, which are found in a manuscript of Kittel (P. v, Appendix, Nos. 1, 3, 6, 7, and last) and in a copy by Forkel (P. vi, 26).
They are quite different from those which he wrote in 1706, upon his return from Lübeck, and which so scandalized the parish, confusing the congregation by their ornamentation.
[REGISTRATION AND ORNAMENTS OF BACH’S ORGAN WORKS]
It is well known how important is the rôle played in the execution of organ music by the registration, and the skilful combination of the keyboards.
Bach left but few directions upon this subject; but with their aid, and the assistance of other hints derived from tradition or found in works of that period, and by placing before the reader the specifications of the principal organs which Bach may have had at his disposal during his long career, we will try to form an idea of what Forkel calls "the exquisite art with which he combined the various registers of the organ, and his manner of treating them."[148]
And our task is now the more delicate, because we cannot draw our conclusions from expressions which bore, at Bach's time, a significance quite different from that which we ascribe to them to-day. Furthermore, we would not lay down any absolute rules in the matter, which in truth is, above all, subjective, the artistic province of the executant. We shall simply point out what Bach indicated in certain definite instances; and, on the other hand, that which was customary at his time. In fact, in authoritative works of the centuries just past, veritable methods of registration exist; and without reverting to the documentary evidence (valuable, though too concise), inserted ad hoc by Scheidt at the end of his Tabulatura nova (Hamburg, 1624), we often find, at the head of pieces written at the end of the seventeenth, or during the eighteenth century, indications of the registration to be employed; given by composers less discreet than Bach. Among the number are not a few Frenchmen, and those men not to be despised; on the contrary, we shall prove how Bach frequently borrowed from their highly picturesque art of registration. No wonder if he provoked a renewed interest in their original "mélanges."