The article analyses the features of the crowd scenes’ structure in the operetta “O olmasyn, bu olsun” (1910) by the outstanding composer Uzeyir Hajibeyli (1885–1948), who founded the Azerbaijani professional composer school at the beginning of the 20th century. In this operetta rich in comic imagery, the composer’s style is reflected in choral scenes influenced by harmonious recitatives and musical patterns and analyzed as a philosophical sphere of reflection of events in the comical plane. He also interprets the development of the operetta genre as a genre of contemporary music in the professional traditions of Western European music in Azerbaijan, as well as the features of intonation that are relevant in Azerbaijani folk music in terms of its structure and thematic focus. The purpose of the research is to analyze the modal features of the operetta “O olmasyn, bu olsun”. For this, the variety of characters available in the work, the line of development of these characters as an issue to study the compatibility of the inner world of characters, given both emotionally and comically, come to the fore. It is also noteworthy that the comparison of moods and intonations in the events taking place in the crowd scenes is naturally reflected here. The research methodology draws attention to the comparative and historical analysis of music theory and history of music, axiological and cultural approaches. Here, the principle of using texts in musical scenes reflects the originality of the composer’s style. Our analysis made it important to consider the research of various researchers who adhere to the principle of secularism. The scientific novelty of the research lies in the fact that for the first time in U. Hajibeyli's operetta “O olmasyn, bu olsun”, an extensive analysis of fret features in crowd scenes with different editions was carried out. The emergence of these features also serves as an example for musicians and composers working in the field of musical composition. Conclusions. The analysis of the modal intonations’ features of crowd scenes in the operetta by U. Hajibeyli “O olmasyn, boolsun” shows the clarity of the intonation principles in Azerbaijani folk music from the point of view of the correspondence of images. This aspect also shaped the composer’s intonation concept. Musical materials suitable for the composer’s comedy scene explain the different situations of the protagonist. The article draws attention to the combination of images and choral performance used in public scenes, for example, the combination of mood and intonation. The use of historical, musical theory, composition, modal intonation features on the public stage is more consistent with the fret concept created by the composer U. Hajibeyli.