In 2024 more than 25 million people with a family migration background were living in Germany, representing over 30% of the total population (bpb, 2024). Just as German society is shaped and co-constructed by these individuals, so too are public music schools. As publicly funded institutions with a mandate to serve society as a whole, they are called upon to reflect this diversity. Their role as spaces of (cultural) socialisation further amplifies their responsibility: they not only convey musical knowledge but also co-produce ideas of belonging, participation and normality in a pluralised society. In a country that, due to demographic change, is becoming increasingly dependent on immigration, this responsibility becomes all the more urgent. The project draws on the theory of the postmigrant society (Foroutan), which understands migration as a constitutive element of society and highlights tensions between equality and exclusion. While German sociological research has examined identity, belonging and the ambivalences of integration, music education research still lacks systematic engagement with how public music schools address migration-related diversity, particularly at the level of leadership and institutional discourse. This study responds to that gap. It investigates how institutional knowledge orders construct belonging, difference, and normality and how these constructions shape and are shaped by leadership practices. The study seeks to generate a grounded theory of how public music schools negotiate migration-related diversity, approaching them as sites of societal negotiation shaped by leadership, institutional structures, and discursive framings as the ways migration-related diversity is talked about and made meaningful in institutional practice. The research applies Grounded Theory Methodology in combination with Situational Analysis (Clarke) to map complex social, discursive, and institutional arrangements. To empirically access discourses, it draws on Keller’s discourse analysis, rooted in Berger and Luckmann’s sociology of knowledge and Foucault’s theory of discourse. This triangulated framework allows for a multi-layered analysis of leadership practices as situated, meaning-making actions. The project aims to theorise how migration-related diversity is discursively framed and institutionally negotiated through leadership practice. It is expected to investigate how leadership, discourse, and institutional structures interact in shaping responses to diversity. The study contributes to debates on institutional transformation and the future relevance of publicly funded music education in a plural society. It aligns with the ISME theme Transforming Music Education, particularly within the strand Critical Debates on Music Education for Social Change, with a focus on how music education itself must transform in response to societal diversity.