The article draws attention to the system of musical ornaments given in the didactic standard of the Italian teacher of the mid-XIX century Giusto Dacci. Created in the conditions of the changed practice of performance, where the importance of reading the musical text as close as possible to the composer's intentions, Maestro Dacci's ornamentation system not only offered teachers their unification in the form of abbreviated letter signs, but also set standards for their decoding. In relation to the content of the music theory, section related to the study of ornamentation, the Dacci system has become the organizing construct that has acquired a stable form of didactic generalization. The types of ornamentation highlighted by Giusto Dacci: appoggiatura – accaccatura – mordent – gruppetto – trill, these are the elements of musical theory that retain universality to this day. They were introduced into the didactic standard at a special historical moment of the active creation of methodological concepts that provide theoretical and technological foundations for pedagogical work in professional musical educational institutions in Italy. Such work not only enriched the musical culture of the XIX century. In the formation of basic coloring skills, it remains an important educational guideline today. 1.In music theory, it captures the experience of accurately encoding ornaments. This experience, in fact, is the key to the visualization of an unchanging sound. For musicology, it is of interest from the point of view of studying the history of the formation of the cycle of musical-theoretical disciplines and its content. 2.In educational practice, it expands the existing format of knowledge, opens up the opportunity for teachers to include this educational material in their practical work. 3.In performance, it allows to understand the facets of possible performing freedom in deciphering jewelry in works taken from a particular time chronotope.