Anonymous I and <i>Prologus in tonarium</i>: Changing Interpretations of Music Theory in Eleventh-Century Germany

This article examines the relationship between Prologus in tonarium by Abbot Bern of Reichenau (d. 1048) and the eleventh-century music treatise known today as ’Anonymous I’ (first published by Dom. Martin Gerbert in Scriptores ecclesiastici de musica sacra of 1784). The authorship and dating of Anonymous I are disputed in current historical literature: Abbot Bern himself has been suggested as its author by one scholar, while dates proposed by other scholars range from c1000 to c1100. The situation is further complicated by the possible connexion of Anonymous I both to an interpolated version of Prologus in tonarium and to the lengthy treatise Breviarium de musica by Frutolf of Michelsberg (d. 1103). This article argues that though Anonymous I was probably written shortly after Prologus in tonarium, it was produced independently of that work. Anonymous I was, however, an important influence on the reception of Abbot Bern’s music theory by eleventh-century clerks.