A vexing question in the history of liturgical music involves the relationship between Gregorian and Ambrosian chant, the latter being the music of the archdiocese of Milan, Italy. This thesis shows that the Carolingian period was decisive, and specifically the attempts of Pippin (751-768) and Charlemagne (768-814) to unify the liturgical and musical practices of the Empire. It poses several questions. Can one uncover a pre-Carolingian layer of Ambrosian chant? If so, what were its musical characteristics? Can one show how and when Gregorian chant, the product of the Carolingian period in the Frankish Kingdom, began to influence the Ambrosian repertoire? Because of the conservative nature of the Office antiphons, they were selected for this study. By determining the origins of liturgical practices it was found one could in general uncover which antiphons may have existed before Carolingian times and which came into existence during that period. An analysis was made of the antiphons of the Common of Saturdays, Sundays, and weekdays (Chapter 2), the temporale (Chapter 3), and the sanctorale or feasts of saints (Chapter 4) to isolate the pre-Carolingian material that survived into and through the Carolingian period. Those practices that were not influenced by the Roman rite but imported into the Milanese liturgy from other sources and those feasts proper to the Milanese church contained only music indigenous to Milan and no Gregorian parallels. By contrast, practices borrowed from Rome (for example, Sunday and weekday Vespers) and feasts held in common with Rome contained borrowings from the Gregorian repertoire. In the second half of the study a musical analysis is undertaken. Here the musical characteristics of the Ambrosian style in the pre-Carolingian material are described. Affinities with and direct borrowings from Gregorian chants are outlined. It is shown that the creative period of Ambrosian chant ended with the early ninth century. From then on, the major concern of the Milanese cantors was the preservation of the unique characteristics of their musical tradition.
