The article is dedicated to the memory of the outstanding researcher, teacher, and Doctor of Art Criticism, Professor Natalia Viktorovna Zabolotnaya (1957–2022). One of the most innovative research positions was the use of N. V. Zabolotnaya of structural-typological and historical-functional approaches in a comprehensive study of ancient Russian church-singing literature of the 11th—14th centuries. The involvement of not only notated but also non-notated sources in the orbit of the study made it possible to come to a qualitatively new understanding of the complex interaction between the written and oral forms of transmission of the liturgical and singing culture of the Studian Typicon era. Other important scientific interests of N. V. Zabolotnaya should include the development of the principles of electronic cataloguing of ancient Russian singing books, the study of the history of the formation of the largest collections of singing manuscripts, the study of the aetiology and specifics of late Znamenny Chants (the late “rospevi”), including the Kievan Chant (“rospev”), etc. She organized and directed for more than 25 years the section of medieval music studies, in fact creating an entire scientific school covering all the main areas of research in the field of liturgical musicology—from Byzantine studies to Campanology. N. V. Zabolotnaya is the editor-compiler of several of collections of scientific articles the initiator and organizer of several major scientific forums, for more than 10 years, she served as vice-rector for scientific work of the Gnesins Russian Academy of Music. N. V. Zabolotnaya was an outstanding teacher, having worked at the Department of Music History for 30 years.