Music, especially singing with others, is a highly emotive experience and has been a core of an early childhood education philosophy that has promoted a social image of the child, where children are portrayed as competent communicators, individuals with rights and members of a community. How children think and learn has been an on-going emphasis of educational research. By unpacking a specific project that centred around the development of a song and musical sharing we explore ideas of project-based learning in the 21st-century. We discuss aspects of child-centred activity and argue that the role of the adults is often prominent, especially in the early stages of designing a project. The context of this study was an early learning centre with arts-based paedagogical practices that included a combination of ideas from the past, children's own experiences and more recent research. This contribution offers a nuanced look at a project involving a musician/composer, teachers with specialised knowledge and children accustomed to investigating challenging issues like climate change. Music offers a powerful language for adults and children to tackle 'big' ideas. It encompasses intellectual, social, cultural and emotional processes which are inherently political and the product of all participants.