xxviii, 592 p. : ill., music / This dissertation investigates the music and liturgy of the German Benedictine convent of Kloster Preetz as reflected in three fifteenth-century manuscripts: the Buch im Chor of prioress Anna von Buchwald, an antiphoner and a gradual. Chapter II describes the convent's music and liturgy and the cantrix's responsibilities, showing that the cloister practiced an unusually elaborate liturgy. It examines Anna's account of an episcopal visitation and explains resulting reforms. Chapter III examines the musical and liturgical roles of the cloister's children. I also present evidence of a group of female "professional" singers who contributed to the music on important occasions and examine Anna's descriptions of rules governing children's lives, the training of young cantrices, and cloister entrance rites. Chapter IV presents a physical description of the convent's gradual and antiphoner and an analysis of their scripts and notation, arguing for the presence of a convent scriptorium that fostered a unique notational lineage. Chapter V discusses music for the mass in the gradual, focusing on the genres of introit trope, alleluia, and sequence. A comparative analysis suggests an early and melodically conservative transmission of tropes. An analysis of alleluia assignments suggests a likeness to the manuscript I-Rvat 181 (Erfurt) and to the liturgical predecessor of a repertoire eventually promulgated by the Bursfeld reform. I furthermore describe six previously undocumented alleluias. A comparison of the sequence repertoires of Preetz and Lübeck shows that the cloister maintained a rich and unique selection. A case study of the melody OCCIDENTANA/REX OMNIPOTENS confirms a Rhenish origin for the earliest repertoire. Four unusual late sequences are analyzed for their textual and theological complexity. The cloister's unique version of the sequence Letabundus exultet reflects the convent's Marian devotion, hints at its imperial origins, and serves as self-depiction of the nuns' devotional practices. Chapter VI describes music for the office preserved in the antiphoner. An analysis of a previously unknown office for St. Blaise suggests that it may be a lost composition of tenth-century composer Reginold of Eichstätt. An added proper office for St. Matthias bespeaks a liturgical connection to Trier, likely transmitted through the Bursfeld movement. / Committee in charge: Dr. Lori Kruckenberg, Chairperson; Dr. Anne Dhu McLucas, Member; Dr. Marc Vanscheeuwijck, Member; Dr. Lisa Wolverton, Outside Member