Identity is a powerful concept that influences behavior and health. For over thirty years, researchers in sport psychology have been using the Athletic Identity Measurement Scale (AIMS) as a research instrument providing insights into the relationships between athletic identity and health variables. While musician identity is recognized as an important factor to be investigated in relation to occupational health, there are no known robust instruments like the AIMS in music psychology research. The current study aimed to adapt and validate the athletic identity measurement scale for use with musicians. The AIMS history includes episodes of modifications for performance enhancement of the instrument that resulted in five different models. The validation process includes evaluating the psychometrical properties across all five models. The sample included student musicians and non-student musicians (N = 1040). The traditional confirmatory factor analysis (CFA) and the maximum likelihood (ML) estimation method were used. The exploratory structural equation modeling (ESEM) and robust weighted least squares (WLS) was utilized to explore a new method of estimation that was known to resolve issues consistent with the CFA and ML method. The goodness-of-fit indices of CFA and ESEM were compared. The results showed that the MIMS is a reliable and valid …