Partial signatures as transmitted in the Buxheim Organ Book and its concordances

In her 1960 dissertation on the Buxheim Organ Book, Eileen Southern stated that she felt that the treatment of accidentals was too irregular to make the manuscript useful for research in that field. This is certainly the case when looking at single pieces, and it is very difficult to spot patterns over the whole manuscript through traditional analysis. However, techniques in computer-aided symbolic music analysis now allow us to search for patterns in large datasets, in this case the Buxheim Organ Book and almost all of its concordances, encoded in Humdrum format. In my previous research on cadential accidentals (Acta Musicologica, 2011), clear patterns of notation emerged, allowing me to reconstruct the decisions made by the main scribe of the Buxheim manuscript, contrasted against the background of its concordances. In this article I apply a similar method to the analysis of signature accidentals: notated in Old German organ tablature, Buxheim has no signatures; accordingly, all accidentals must be explicitly notated. Through computer-aided analysis, I found patterns in how signature accidentals from sources in mensural notation are translated into organ tablature. These patterns inform our understanding of the prescriptive nature (or not) of partial signatures, cancellation of signature accidentals for cadential and other purposes, transposition, and the scribe’s possible attitude to modal identity and classification.