Source: Die Nothwendigsten Anmerckungen und Regeln wie der Bassus Continuus oder General-Bass wol könne tractiret werden (Ascherselben: 1698)
Werckmeister’s treatise on playing continuo includes an appendix entitled Kurtzer Unterricht und Zugabe wie man ein Clavier stimmen und wohl temperiren könne, which he says he feels he must include precisely because the novice may not know what a “tempered keyboard” is. It is very interesting that this temperament is both more elegant and – for a novice – considerable more complex than his famous quasi-circulating “Werckmeister III”. His instructions are somewhat open to interpretation, but the possibilities always remain within certain limits which are fairly easy to determine. At its most conservative, it resembles the mollified meantones of the French authors, although the worst tonality is shifted one fifth to the left, from G# major to C# major, making the first flat keys a bit better. When pushed to the other extreme, it begins to resemble the quasi-equal rational circulating temperaments of Neidhardt and Sorge. I provide it here in five different versions, from more-meantone-like to more-equal-like.
Disclaimer: the attribution of comma fractions to the tempered fifths is done by an automatic table look-up function. If the exact value is not in the table, the system grabs the nearest lower value. Naturally, my table does not have all possible fractions of both commas for both narrow and wide fifths. Therefore, with all modified meantone temperaments, for those fifths which “close the circle”, i.e. fill in the gap left by the departure from pure meantone logic, the amount of tempering has been somewhat arbitrarily chosen, exactly as one does when tuning an instrument, although in this case, working with decimal values for the proportion of the fifth. Therefore, the final size may not represent any fraction of any given comma, and there is no guarantee that the amount of tempering indicated as a comma fraction in the graphic is precise. The value indicated in cents, however, is derived from the proportion, and is therefore completely trustworthy.