The article is devoted to the consideration and study of the creativity of the most prominent representatives of the musical art of national ethnic groups, the role of the Assembly of the People of Kazakhstan, the identification of various criteria for the relationship of ethnic groups living in the territory of the Republic of Kazakhstan, the peculiarities of their life, way of life, spheres of life, their relationship and views on the modern State, created by the first President of the Republic of Kazakhstan – Nursultan Nazarbayev. The core of the projects completed in the period from 2012 to 2017 includes not only historical facts and materials found from the State Archives, Central Scientific Library and the National Library of the Republic of Kazakhstan, but also an overview of active participation in many events related to the Assembly of the People of Kazakhstan, to the 20th and 25th anniversaries of the Assembly of the People of Kazakhstan, associated with the considered ethnocultural centers and representatives of certain ethnic groups. Through the media, participation in international scientific and practical conferences, previously unknown facts of the studied ethnic groups were highlighted, and their relationship with the main population of the republic, their contribution to the multinational culture of Kazakhstan, which in turn confirms the prudent, orderly, and wise policy of Elbasy (The Head of the State). The authors use the following methods in the study: historical-chronological, source study, analytical, comparative, and interviewing. Since 2012, in Kazakh musicology, the musical heritage of ethnic groups inhabiting Kazakhstan has been studied. A unique opportunity for a full-fledged study of their work is presented thanks to the activities of the Assembly of the People of Kazakhstan and systematic state policy, under the leadership of the First President. In 2017, the second book, entitled "The Historical Significance of the Assembly of the People of Kazakhstan in Interethnic Cultural Integration", was published, which became a fruitful result of the research project in 2015–2017. This book is a kind of continuation of the series, which began in the previous collective monograph "The Musical Art of the People of Kazakhstan", which was published at the end of 2014 and has undergone extensive testing not only among professionals, but also among fans of the musical culture of multinational Kazakhstan. Such research projects, which were not previously carried out in the domestic humanitarian science, are significant and in demand, since before their appearance in domestic musicology there were only separate reports on the activities of cultural centers, articles in the media and on Internet sites, a brief analysis of the work of specific masters in publications devoted to the study of the history of musical art of numerous national cultures. They give only fragmentary ideas about the art of the ethnic groups in question. The relevance and insufficient elaboration of these problems served as the basis for the study "The historical significance of the Assembly of the People of Kazakhstan in interethnic cultural integration", carried out by the Department of Musicology of the M. Auezov Institute of Literature and Art of the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan. The implementation of such a complex and significant topic for the national musical art, coverage of the activities of large cultural centers of different ethnic groups, and much more makes it possible to determine the contribution of each of them to the history of Kazakhstan's development and outline ways to preserve the traditional folklore heritage and identity. In this regard, these projects are relevant and socially and politically significant at the state level.