Following the Council of Basel in 1439, which initiated the papal schism between Eugenius IV and Felix V (Duke Amadeus VIII of Savoy), Guillaume Du Fay appears to have resumed his northern connections, leaving the court of Savoy and returning to the patronage of the Duke of Burgundy. This article sheds new light on the timing of the composer's move, and on his continued contact with the court of Savoy during the schism of the 1440s. Examination of liturgical sources from the cathedral of Cambrai and elsewhere brings to light a liturgical and musical anomaly in Du Fay's polyphonic settings of Mass Propers for St Maurice, composed during this period, suggesting that this cycle may have been commissioned from Savoy, although Du Fay seems to have had access only to Cambrai chant sources for its cantus firmi.

This article examines aspects of variation and transmission in the Office of Thomas Becket in the Diocese of Trier, Germany. Palaeographic evidence suggests that by the mid-fifteenth century, liturgical sources in Trier exhibited numerous transmission errors and disruptions in the modal scheme of the Thomas Office. However, a subset of late fifteenth- and early sixteenth-century manuscripts from St Florin and St Castor in Koblenz displays efforts to restore the theoretical modal scheme of the Office by composing new melodies for four items; the uniqueness of these items has been confirmed with the assistance of a large-scale electronic project cataloguing the Office of Thomas Becket across Europe, headed by Andrew Hughes at the University of Toronto. The present study provides a detailed melodic and modal analysis of the four newly composed items: the invitatory, Adsunt Thome martyris; the fourth responsory for Matins, Post sex annos; the ninth responsory for Matins, Iesu bone per Thome; and the fourth antiphon for Lauds, Ad Thome memoriam. Numerous melodic allusions to the Office of St Gorgonius – a martyr also venerated in Koblenz from the turn of the fifteenth century – have been uncovered in the four newly composed items. The re-ordering of the modal schemes of the Thomas Office and the colourful array of musical and theological echoes and allusions between the Becket and Gorgonius Offices suggests a desire to establish, reflect and cultivate a local liturgical identity within the community in Koblenz.

The basis of this study comes from the great responsory repertory in the twelfth-century French monastic manuscript, Paris 12044 from Saint-Maur-des-Fossés. A computerised database containing each component phrase was used to create a more accurate melodic taxonomy of responsories than has hitherto been available. Building on the research of W.H. Frere, H-J. Holman, and others, it is possible to obtain clearer insight into formulaic composition in an oral culture. This is achieved by comparing the use of recurrent, or ‘standard’, musical material in Paris 12044 to that found in several other manuscripts. The presence of standard material in a respond melody is found to be linked to the consistency of form and tonal structure.