The topic of this thesis is teaching and learning of modulation examples within the ear training lessons, using different solmization systems. In addition to defining, describing and comparing the main characteristics of the solmization systems as such, the thesis presents an overview of the similarities and differences in approaches to modulation as a specific aspect of the ear training process. Modulation examples are taken from the music literature: every example consists of a short theoretical analysis (melody, harmony, musical form), and a longer review of using various solmization systems with their advantages and disadvantages, viewed from a didactical perspective. The thesis also provides specific exercises that will improve the processing of the chosen music examples, regarding the characteristics of the examples themselves, and the chosen solmization system. Furthermore, the thesis contains an analysis of the official Ear training curricula in Croatian music schools (elementary and highschool level), focusing on the order of teaching and learning modulation within the tonal context (major and minor). Suggestions for possible changes of the curricula are concluded in the analysis, with the aim of developing more effective teaching and learning methods.