This study explores how participatory music programs can help build social connection for people experiencing loneliness in contexts of social marginalisation. Loneliness is a growing, global public health issue with social and structural drivers. There is an urgent need to investigate innovative approaches to programming that go beyond opportunities for social contact to address the multiple domains of loneliness. Designed collaboratively with two social sector organisations in an urban context in Australia, this study presents outcomes from two community programs that involved groups of people experiencing or at risk of loneliness engaging in music together. Using a qualitative methodology that included semi-structured and brief interviews, focus groups and ethnographic observation, researchers identified positive shifts in relation to social loneliness (related to social contact), emotional loneliness (related to social bonds and meaningful connections), and existential loneliness (related to community connection and acceptance) for participants of the music programs. This study contributes to an urgent gap in understanding effective programming to support people experiencing loneliness and bolsters emerging evidence about the role arts can play in strengthening health, community and social sector efforts to address inequity.