Gallus Huszár’s Debrecen church hymnal (1560/61) is a rich source for 16th century Hungarian Reformed service singing, uniquely distinguished by its musically notated melodies. The current study investigates its so-called rubrics, short (or sometimes longer) liturgical annotations, which, on the one hand, outline the course of the church services of his era, and, on the other hand, provide a glimpse into the contents of the individual liturgical moments, both on a theological and an emotional (or poetical) level. They allow us to distinguish the genres of hymns used within the worship services (chief services, canonic hours, para-liturgical occasions). The current article would like to contribute to the renewal of today’s Reformed worship that is long overdue, and which ought to follow the spirit of the Reformation. One will find here the most important pieces of information, as well as the inspirational bases for such a reform.