Project TREBLE (Testing Resilience in an Ensemble-Based Learning Environment) is a 3-year longitudinal study funded by the Ware Foundation. The purpose of the study is to examine in a multifaceted manner how participation in the Miami Music Project (MMP – an El Sistema inspired program) impacts the lives of youth. We will recruit MMP students (ages 8-17) and their parents, as well as their MMP music instructors. We will follow these families over the course of a year and examine how these children are impacted because of their involvement in in MMP. This project involves collaboration between state-of–the-science researchers and state-of-the-art music educators. Our community collaborator is the Miami Music Project, which was founded by world-renowned conductor James Judd. The MMP program provides free music education to Miami youth, following the El Sistema philosophy. El Sistema was founded by economist and musician, José Antonio Abreu, with the idea that social change could be achieved through the pursuit of musical excellence using a rigorous ensemble-based model of instruction. This program has been quite successful in Venezuela and in other countries and its implementation is burgeoning in the United States. MMP has already become one of the largest El Sistema inspired programs in the United States and currently has a total of 300 students (ages 5-18) participating across two chapters in Miami-Dade County. However, despite international enthusiasm about El Sistema, there are almost no empirical data documenting the impact of participation. The primary aim of this study is to examine the impact of participation in the MMP program on key factors identified as critical for successful positive youth development programs namely Competence, Character, Confidence, Connection, and Caring as well as executive functioning. This study will provide critical information needed to elucidate in what ways participation in an ensemble music program enhances the lives of youth.