This article reports on a year-long project carried out in three UK primary schools, which aimed to understand the expectations and experiences of children participating in a series of workshops delivered by the chamber music organisation, Music in the Round. Through drawings, discussions, questionnaires and observations, the children's developing musical identities and skills were explored, alongside the teachers' and parents' understandings of what the children gained from the workshops. The project raises questions about the evaluation and impact of musical interventions of this kind, and about the ways in which children acquire musical self-efficacy from encounters in school and home.