Foreword: Eastern Orthodox Church Chant at the Crossroads of Traditions / Part I Studies on Genre / Psalm 140: Versions and Redactions (1995) / The Kekragaria in the Sources from the 14th to the 19th Century (1997) / The Akathistos Once Again (1998) / The Byzantine-Slavic Sanctus: Its Liturgical and Musical Context (1998) / Part II Studies on Liturgical Books / The Tropologion: Sources and Identifications (2018) / The Tropologion Vaticanus Graecus 771 (2020) / The Tropologion Vaticanus Graecus 2008 (2011) / The Notated Repertory in the Early Oktoechoi Revisited (previously unpublished) / Studying the Oktoechos: from the Oktoechos to the Anastasimatarion (2010) / Part III. Studies on People / St. Cyril and St. Methodius: The Roots of Slavic Orthodox Church Chant (previously unpublished) / Metropolitan Theoleptos of Philadelphia: Between Tradition and Innovation (2013) / Hieromonk Evstatie of Putna: The Putna Music School Revisited (previously unpublished) / Metropolitan Serafim of Bosnia: The Graeco-Slavic Contacts in Balkan Orthodox Church Chant (2018) / Part IV Studies on Bulgarian Orthodox Church Chant / Melismatic Chants Related to Bulgarian Church Chant up to the Fifteenth Century (previously unpublished) / Musical Performance from the Fifteenth Century (previously unpublished) / “Bulgarian” Chants in Musical Manuscripts (2013) / The Transition from Monophonic to Polyphonic Church Music: The Case of Bulgaria (previously unpublished)