Best known today for his work on music of the nineteenth and twentieth centuries (especially that of Mahler), the Hamburg-based musicologist Constantin Floros has also made fundamental contributions to the study of Christian plainchant, especially of the Byzantine and Slavonic liturgical traditions. His Canadian student Neil Moran, who in 2005 took up the long overdue task of making Floros's chant scholarship available in English with a translation of Einfürhrung in die Neumenkunde (published as Introduction to medieval notation, 1980), offers here a collection of writings exploring the musical repertories and notation of five Slavonic musical manuscripts dating from the eleventh to the thirteenth centuries. Often described as ‘Kondakars’ because of their melodically florid cycles of kontakia (a Constantinopolitan genre of hymns), these manuscripts were, during the 1960s, independently shown by Floros and Kenneth Levy to be Slavonic adaptations of lost predecessors to the Asmatikon (a choirbook for the rite of Hagia Sophia also employed in Stoudite monasticism), employing a form of notation related to the ‘Chartres’ family of Paleobyzantine neumes. Since extant Greek copies of the Asmatikon lack kontakia, this identification was made on the basis of textual and notational correspondences with the Kondakars' other repertories of hymnody and psalmody. Furthermore, the matching of melodic formulas in the Greek manuscripts, which employ intervallically precise Middle Byzantine notation, with groups of musical signs in the previously indecipherable kondakarion notation was shown to allow at least partial transcription of the Slavonic items. In the present book Moran offers English versions of three seminal studies by Floros – the meticulously detailed ‘Die Entzifferung der Kondakarien-Notation’, originally published in volumes iii (1965) and iv (1967) of Musik des Ostens; and two brief chapters from his monumental Universale Neumenkunde (1970) refining his exposition of relations between Byzantine and Slavonic chant – as well as a new foreword by the author, an English version of a 2007 article by the translator comparing Ambrosian, Slavonic and Greek versions of a famous ancient chant for Holy Thursday from Jerusalem (‘Coenae tuae’), and a bibliography of ‘Recent publications on Chartres and Kondakarian notation’. Much of the earlier material is only sparsely annotated, leaving the reader to discover the basis for revised conclusions only upon reaching the chapters from 1970 that discuss Kastoria 8, a then newly-discovered Greek Asmatikon in which many chants feature an extra row of musical signs resembling those of the Kondakars. A light editorial touch is also evident in the book's occasional awkward passages of English prose, non-standard (at least for Eastern Orthodox readers) liturgical terms, misprinted examples and typographical errors. Nevertheless, Moran should be commended and encouraged to continue his valuable translation project.