Carnegie Hall’s Lullaby Project brings well-documented benefits of music-making to the urgent work of supporting the well-being of young families, both caregivers and children. It is also one of the collaborating partners in REACH’s program of investigating and documenting how access to high-quality arts experiences can counteract the consequences of developing in circumstances curtailed and distorted by structural inequalities. At the end of May, the growing international network of Lullaby Projects came together in New York to share project strategies and outcomes. Half a day was devoted to exploring how the naturally occurring materials of Lullaby Projects (e.g., lyrics, interviews, play sessions between caregivers and children) can be used to document and research the impact of such projects. REACH-affiliated researcher Dennie Palmer Wolf, alongside early childhood educator Linda Russell, shared original interviews and early findings on how mothers’ self-efficacy and role satisfaction grow throughout the project. Additional Reach researchers Kate Anderson and Anusha Mohan used project data on play interactions to explore how the mutuality of caregiver-child interactions, along with caregivers’ reflectivity, increase across the sessions. Some of these early findings are shared in the recently published volume from Oxford University Press, edited by Rosie Perkins, Music and Parental Mental Well-being.