Adhering to the contention of Leo Treitler that history is made up of a totality of records that include knowledge of history and that music, as well as writing about it, are in interaction with the society and culture of its time, then definitely, when presenting cultural achievements in northern Croatia during the 18th c., texts on music in Latin script should also be included. This is primarily because they represent the only preserved sources of the formalised and official discourse on music and thus enable research not only from their theoretical precepts of projected music practice, but also of the patterns of cultural and social life of northern Croatia connected to it right before Josephinism. Since in former musicological research they have been left without an in-depth analysis of thought on the music they were promoting, they need to be read in order to better comprehend its role in the daily routine of an average man (evenly in urban and rural regions) who, most frequently came into contact with it in the context of church ceremonies. At the same time, one should be aware that this is church liturgical and paraliturgical music, not folk or artistic music. In that sense, this dissertation pursues a detailed analysis of the introductions of all the three editions of the proceedings Cithara Octochorda (Vienna 1701 and 1723; Zagreb 1757), of the manual by Mihael Šilobod Bolšić Fundamentum cantus gregoriani seu choralis (Zagreb, 1760) and, to the extent of partially available content, of the manual by Tomo Kovačević Brevis cantus gregoriani notitia (Vienna, 1701). The texts whose main theme was music, whether as musica theorica or as musica practica, published in Zagreb and Vienna from 1701 to 1760 were written in Latin script and encompassed two fundamental forms of music discourse. One deals with music in a pedagogical sense (musica practica) and we find it in manuals for teaching Gregorian chant of Tomo Kovačević Brevis cantus gregoriani notitia (Vienna, 1701) and Mihael ŠilobodBolšić Fundamentum cantus gregoriani seu choralis (Zagreb, 1760). The other promotes music as an aspect for strengthening oneꞌs devotion to God, a tool in regulating the emotions and behaviour of the individual and a direct connection with God, on the trace of the mediaeval musica theorica. Such a discourse is present in the prefaces of the most significant musical venture of the first half of the 18th c. in northern Croatia – proceedings Cithara octochorda. The first chapter titled “Historical and geographical positioning” presents an historicogeographical frame in which the mentioned texts have been written, as well as the general social and cultural climate in which their authors have worked. Likewise, the first chapter defines the terminology of the specific period, that, in Croatian lands, according to the former learnings and research of the author, unequivocally is defined as “Catholic restoration”. The second chapter analyses past research that is directly or indirectly connected to our theme: describes Croatian sources that are the immediate subject matter of this dissertation, the research of the Gregorian chant in Europe and the place that belonged to domestic sources in local music historiography until this research. The third chapter of the dissertation initiates a critical analysis of the discourse of the texts we have been writing about, thus challenging the present epithet of anachronistic music activity that Croatian music historiography accredited to music practice in northern Croatia in the first 60 years of the 18th c. The third chapter defines the frame of the music theory knowledge and the manner of appraising music as an ethical and practical activity. The music theory frame in the sense of corpus of knowledge is analysed based on the definition of the manner of writing texts offered by St. Bonaventure, to be more precise, within the procedure of compilation (compilatio) that is the fundamental manner in which church writers compile their tractates. The analysis is conducted by revealing direct or indirect allusions to authors and their works (probati auctores) among which most are, along general references to antic authorities such as Plato and Cicero, from neighbouring Italy. The manner of presenting knowledge is analysed in the fourth chapter in the context of the idea of dominant epistemologies of the 16th, 17th and 18th c. as defined by Michel Foucault. In so doing, the argument on the coexistence of disparate models of music theory discourses has been confirmed which was indicated by Carl Dahlhaus. A comparative analysis of the texts published in the neighbouring countries has shown that it is not an anachronistic, but solely stylistically limited type of music theory discourse that, in manuals accepts the contemporary manner of expressing knowledge that is distinguished by order, regardless whether it is shown in a table, sequence or mnemonic verses and exists in all European Catholic countries. The fifth chapter discusses the similarities (similitudo) as the fundamental manner for connecting words and things that Michel Foucault attributed to episteme. The analysis of the introductions of proceedings Cithara octochorda comparative to a certain model, the proceedings Lyra coelestis published in Trnava in 1695, demonstrates a similitudo in the discourse on music even in the post-Renaissance period, but also denotes its significance in ix the discourse shaped in patristics and the Middle Ages. In addition, by investigating the general places such as affected modesty, utilitas and pietas, a strong influence of antic rhetoric theory is pointed out. In the final sixth chapter, the relationship between musica theorica, as a speculative discourse on music and musica practica, as a didactical discourse that finds its foundations in manuals that emerged in the period of the Carolingian state is being analysed. In the didactical discourse there is an equal intertwining of the medieval fundamentals of music theory (the hexachord system, alphabet, solmisation, keys, names of modes) and Renaissance elements in metre (division of brevis, rhythmisation of chants according to poetical metre and not by accentuated markings in the text set to music) and the modal system (hexachord modal system that uses old-Greek terminology). Aesthetics on the other hand in the discussions on music, and not in the chants themselves, is reduced to an ethical role of music in the life of an individual, its healing and soteriological power, since, as a direct physical manifestation of the metaphysical, it rules the microcosmos. Accordingly it became a significant means in the process of catholic restoration that during the first half of the 18th c. in some elements became compatible with the enlightening absolutism of the Habsburg Monarchy that was strongly tied to the Catholic Church.