Practice is essential to the acquisition and development of musical skills, requiring musicians’ time, investment, application, motivation, metacognitive strategies, and ability to self-regulate. Research in children’s music practice indicates the type, quality, and duration of practice, along with adult support, contributes to fluency in musical development; and when progress occurs, children invest in further practice. However, nuances in children’s lived experiences of musical practice that influence these critical factors are largely unknown. To understand the complex issues in children’s practice, this study employed a unique pairing of Interpretative Phenomenological Analysis and Participatory Action Research to investigate 14 seven-year-old beginner cellists’ practice during early learning and explored how their thoughts and experiences evolved over the first 18 months of lessons. Providing rare insight into children’s perceptions of musical development and the vital role of parents and teachers in nurturing engagement, three superordinate themes emerged: (a) four approaches to practice, characterized by practice structure, learner behavior, and family support, (b) a three-phase practice process, and (c) perfection ideation. Positive experiences, including creative activities, within these thematic contexts fostered children’s enjoyment in early musical development, supported productive learning interactions, and sustained engagement. Together, the findings have meaningful pedagogical implications for instrumental music teaching practice.