In this paper we present a commented translation of the Cento Concerti Ecclesiastici (1602), by Lodovico da Viadana (1564-1645), the first sacred work to bring a set of written instructions on the accompaniment that would be known as thorough-bass. Through the study of the original source, together with modern sources about the practice, which it describes, we seek to contextualize and interpret the information found in the text. Furthermore, we propose a reflection on the influence of this work in the development and consolidation of harmonic practice that would characterize the musical writing and accompaniment throughout the Baroque period.41