Research on teaching and learning in integrated education has focused on connections between arts and non-arts domains to provide a comprehensive experience for K-12 learners. Recently, STEAM (Science, Technology, Engineering, Arts, Mathematics) education has explored arts integration for more effective STEM learning. However, effective integration is often elusive; the arts are sometimes diluted as a consequence of well-intentioned integration within STEM subjects, with STEM learning risking similar superficial treatment within arts curricula. This qualitative pilot study focuses on The EcoSonic Playground Project (ESPP) -- an integrated STEAM project for students of all ages -- and evaluates its effectiveness from a co-equal integration standpoint, where participants use skills across STEM and arts areas equally in service of a common, musical goal. Findings suggested that this project supported, the application of existing cognitive and social-emotional skills and STEAM practices within an arts framework while fostering in participants the synthesis of new connections among skill areas. While recognizing findings are context specific, conclusions and recommendations may be of particular interest to educators and researchers exploring STEAM or other arts integration initiatives in the classroom.