Implicit theories of musical ability, music self-concept, and musical sophistication are important factors that shape music participation and self-regulatory development. Although extant research has examined the link between musical outcomes and either implicit theories of musical ability or music self-concept, the direct relationships among these variables and how those relationships may be disseminated across general populations remains underexplored. The aim of this research was to design and widely disseminating a survey instrument that measures these variables within middle school students.The purpose of this study was to examine the prevalence and relationships of implicit theories of musical ability, levels of music self-concept, and levels of active musical engagement and music backgrounds within the general population of students attending public middle schools in the United States.The following research questions were addressed:1. What is the predominant implicit theory of musical ability, level of music self-concept, and level of musical engagement and music participation for the general population of middle school students?2. Is there a relationship between implicit theories of musical ability and levels of music self-concept and engagement? 3. Is there an interaction effect between implicit theories of musical ability and music self-concept on levels of musical engagement?Students (N = 300) enrolled in public middle schools participated in this research. Surveys were administered to participants during compulsory music courses at their respective schools. I sampled students (grades 6-8) from required music courses to get the broadest representation of student backgrounds from each school site.Participants completed a survey that collected musical background information. The survey also measured entity mindset using the Implicit Theory of Musical Ability Scale (ITMA), adapted from Dweck’s (1999) Theories of Intelligence Scale. Participants completed the Music Self-Concept Inventory (MSC; Hash, 2017) and responded to musical training and active engagement items from Goldsmith’s Musical Sophistication Index, v.1.0 (Müllensiefen, Gingras, Musil, & Stewart, 2014).Early results show that middle school students demonstrate low entity theories of musical ability and high levels of music self-concept. There does not appear to be a relationship between implicit theories of musical ability and music self-concept nor between implicit theories of musical ability and musical engagement. However, there is a significant correlation between music self-concept and musical engagement. Findings from descriptive and regression analyses along with responses to the research questions will be discussed during the presentation. Word Count: 386