This passage is from the last few pages of Sorge’s Zuverlässige Anweisung, Claviere und Orgeln behörig zu temperiren und zu stimmen, his very amusing and at times quite bitingly sarcastic critique of Bartold Fritz’s 1757 Anweisung, wie man Claviere, Clavecins, und Orgeln, nach einer mechanischen Art, in allen zwölf Tönen gleich rein stimmen könne. Translation by Paul Poletti
[After describing the various temperaments marked out in the copper plate plan for a monochord found in the back of the book] With such a monochord, one can examine a tuning, [and find out] if it is equal or unequal, [if it is] useable or if it should be abandoned.
Would that it were so that all those that have to do with the harpsichord and organ, those who play or build, understood this, nor would it be a bad idea for other musicians as well, actually, very useful.
I have already had to send this kind of monochord to many well-known cities in Germany, and here and there they have already been of great usefulness, which I can prove by means of the many letters written to me on this. With this monochord, one can observe visually how much an interval can and must deviate from its natural purity, and the strings which are mounted thereupon demonstrate the veracity of the case. One has mathematical proof of everything which has been said here above, and at the same time one is assured against all the deceptions of the ear. The copper engraving appended to this book offers a better understanding thereof. Additionally, one must know that the total length must contain within itself four times 500 divisions. Whoever requires more information about this can notify me in writing, and he shall be well-served.
Special report on a Temperament Pipe
Because an organ pipe cannot be tuned well from a string, due to the fact than the sound of the string dies away quickly and that the string can easily become detuned, I therefore thought, could one not mark a calculated temperament on the stopper of a so-called tuning pipe, by means of a ruler designed for this, in much the same way that one can mark the temperament already tuned on an organ? And see! It works just as desired! However, for each organ, a unique tuning pipe must be made, since the wind in one instrument is thus, and in another so.
The method and manner of how it is made is a simple task for those who are familiar with the topic, and they will be able to make the special ruler which is required there for. Its length will depend upon that of a purely-tuned octave, and this length is divided into 1000 parts. The short end of the octave is equal to 1000, and the large 2000; within this space, the 11 intermediate [notes] are distributed, according to the temperament which has been calculated between 1000,00 and 2000,00.
In this manner, the so-called gleichschwebend or equal temperament, or any other “good” temperament, so to speak, can be brought into reality, and one can precisely examine a pre-existing temperament, how it has been done and how and where it can be improved. Mr. Adlung, organist in the Prediger Church in Erfurt, etc, also describes this sort of Tuning Pipe in his Manual of Musical Knowledge, p. 312. I had already made such a thing before I had seen this admirable book.
He who does not yet understand this clearly, and would like to comprehend and understand this useful thing, is kindly requested to inquire it of me by prepaid post.
Wouldn’t it be a wonderful thing if one could convert a previously realized temperament of an organ into measures and lines, or in reverse, apply the measures and lines to an organ? Wouldn’t the pure harmony be thereby clearly conveyed?
Of what use are all the measures and lines if the musical intervals aren’t arranged according to them? Surely they can convince the intellect and the eye as to the necessary conditions, but without strings, pipes, and song, they are of little help. The monochord can certainly be of service to those without sufficient practice when tuning stringed instruments, but tuning pipes thereto just doesn’t work very well, as already mentioned. However, it is easy to tune [a pipe] according to another pipe which has been properly divided. Having done this, one will become completely convinced of the important service proportional calculation has to offer our sense of hearing, and equally so, how our sense of hearing can be cautioned against taking the wrong path. Therefore this is highly recommend to our good reader.