The purpose of the research is to highlight the prerequisites and conditions for the development of organ and singing performances of Roman Catholics in Galicia at the intersection of the nineteenth and twentieth centuries, which influenced the current state of church music development. Research methodology. Based on the principles of objectivity and impartiality, the prerequisites for the development of Roman Catholic music in Galicia since the nineteenth century are considered. The comparative-historical method is used to draw chronological parallels of introducing the Roman Catholic rite to Ukrainian and Polish lands. The structural-functional method was used in the consideration of the process of liturgical performance traditions’ renewal of Roman Catholic music, which began in the nineteenth century and appeared in Galicia due to close interaction with the countries of Western Europe. The influence of the Caecilian and Bernardine movements on sacred art is noted. The historical and retrospective method was used to recreate the historical and social problems of the development of spiritual art in the 19th-20th century. The local and Western European resolutions of the 20th century and several official documents that influenced the renewal of church performance were emphasized. The socio-cultural method was used to indicate the influence of organ schools of the leading musical and educational centers in Lviv, Krakow, Tarnow, and Przemyśl on the improvement of the professional competence of performers. The cultural method was used to cover several artistic and spiritual events with the participation of secular and spiritual groups, thanks to which previously unknown composers have been introduced into scientific circulation. The scientific novelty of the research is that the article highlights the historical and cultural poly-confessional specifics of different ethnic groups' coexistence in the little-studied Galicia. The state of liturgical practice in the Roman Catholic rite is presented, the reasons for the emergence of the Caecilian movement in Europe and its influence on Roman Catholic church singing traditions in Galicia are illuminated, and the importance of official documents of the RCC is emphasized. Some vocal and choral educational institutions and schools for organists in Lviv, Krakow, Przemyśl, and Tarnów were mentioned. Attention is drawn to the intensification of the organization of musical life in the region and the emergence of publishing houses that contributed to the rapid reform of Roman Catholic liturgical performance since the nineteenth century. Conclusions. As a result, it was noted that the church music of the Roman Catholic rite of Galicia in the twentieth century underwent significant updates, returning to Gregorian chant and the canons of polyphonic liturgical music, and the improvement of the level of organ and singing performance led to the study of relevant subjects in modern universities.