Belfast, 2-4 November 2007


Parallel proportions, final revisions and the status of the manuscript P180

Ruth Tatlow

(University of Stockholm, Sweden)

When creating an instrumental collection Bach frequently grouped together works he had composed earlier, adding and deleting bars and new movements as the collection took shape.  As the recently-published theory of proportional parallelism shows, there is a very special numerical characteristic common to all of the instrumental collections that Bach published or left in fair copy: all of them have several levels of 1:1 or 1:2 proportions formed by the number of bars.  Since these proportions are usually absent in Bach’s composing scores, it can be deduced that Bach created parallel proportions at the final stages of revising and perfecting a collection.

The B-Minor Mass can be considered a collection insofar as it comprises multiple movements, and four parts.   The manuscript of the B-Minor Mass, P180, however, is neither in fair copy, nor was it published in Bach’s life-time, and thus, according to the new theory, one would not expect to find parallel 1:1 or 1:2 proportions in it.   On the other hand, the revisions Bach made to P180 are so extensive and some made so late in his life, it has to be asked whether Bach considered the score to be the equivalent of a fair copy, in spite of its unpolished calligraphy.  Using the principles of proportional parallelism, this paper will examine the bar structure of the 1733 Missa and the 1749 B-Minor Mass to see what light the results can shed on the status of the scoreAt its simplest, a lack of proportions will show that Bach had not finished revising the numerical structure; and conversely, the presence of several levels of proportion will demonstrate unequivocally that Bach considered the work numerically perfect, and ready to publish.

Last updated on 24 June 2007