The mass-proper cycles of Henricus Isaac : genesis, transmission, and authenticity
This study reassesses the relationship between the monumental collection of Henricus Isaac's mass-proper cycles published as the Choralis Constantinus and the composer's original massproper projects. The first section charts changing views of Isaac as a historical figure, from his time to ours. Following this, the second section pursues the implications of recent redatings of major Choralis sources with a detailed investigation of the transmission of the Choralis' s music from composer to print. This analysis suggests new views for the make-up of each of the projects known to have been compiled together in the print: the earlier theory of a Constance Common of Saints is dismissed, whilst a mass-ordinary that may have belonged to the Constance project is identified; it is suggested that Isaac's mass-propers for the Imperial court cannot easily be seen as a single project, and that some anonymous propercycles not found in the Choralis may be Isaac's and may have belonged to Imperial repertory. To shed further light on the original scopes of Isaac's mass-proper projects, the third section of this thesis investigates Isaac's non-Choralis mass-propers. Particular attention is given to the large collection of such items found in two related manuscripts from latersixteenth- century Augsburg. Examination of the context and function of these manuscripts suggests that the unica they preserve attributed to Isaac are spurious. On the other hand, consideration of the Choralis's transmission and the shape of Isaac's secure Imperial repertory suggests that some anonymous cycles in the manuscript WeimB A are Isaac's. The final part of this study re-examines the attributions and de-attributions made in the first two sections at a music-stylistic level. No conflicting evidence is found. On the contrary, all earlier suggestions are reinforced.