Medieval and modern manuscripts, letters and diaries of famous people, games, picture sheets, sheet music, and, of course, books in all formats—anyone who explores library collections encounters a wide variety of treasures of cultural heritage, some of which are truly astonishing. There are many facets to managing these collections, which are explored in the traveling exhibition *schrift : buch : kultur*, conceived by the Working Group on Historical Collections in the Libraries of North Rhine-Westphalia and Rhineland-Palatinate: How do we expand and preserve our collections? What must we do to preserve them for the future? How do we make our collections accessible? And what role do old books play in the age of digital reading and AI? As part of its historical heritage, the Mainz City Library’s collection includes over 60,000 printed works from the 16th to the 18th centuries and approximately 1,300 medieval manuscripts. But it is not only the extensive historical holdings that make the collection so valuable and special. On behalf of the state of Rhineland-Palatinate, the library compiles all literature from and about Mainz and Rheinhessen, and has thus served as the cultural memory of the city and the region for over 200 years. This cultural heritage also includes several special collections that are true treasures, such as the Peter Cornelius Archive, the ornithological book collection of Mainz native Jacob Moyat, the theater library, and the Jos. Scholz Collection with its children’s books, games, and picture sheets. Together, the regional, historical, and special collections tell a variety of stories about the regional cultural landscape and give the library its unique character. It is important to preserve this connection.

The Mainz City Library takes visitors on a journey of discovery through its collection, from which it presents selected items as examples to complement the traveling exhibition. One such example is the manuscript *Instructio ad cantum choralem* (Hs IV 157), which the library has owned for just over a year. New acquisitions are added to the manuscript collection only in rare, exceptional cases. However, Hs IV 157 is a choral manuscript with regional significance, which is why it was added to the collection as part of a donation from the Baur Music Foundation and made available to researchers.

Dr. Krystian Skoczowski’s lecture will explore what conclusions can be drawn from this choral manual regarding the practice and teaching of Gregorian chant in the 18th century. Drawing on the manuscript and other regional choral sources from this period, he will outline the musical and liturgical understanding of this art form during the Enlightenment and the Baroque periods.

Krystian Skoczowski is a church musician and musicologist. He serves as cantor at St. Elisabeth Parish Church in Hanau. His artistic and scholarly focus is on researching and preserving the organ heritage of his native Hesse and on the history of the interpretation of Gregorian chant. He is also a member of the Consociatio
Internationalis Musicae Sacrae (CIMS, Rome), editor of its publications, and currently its secretary general.