Background Music is an integral part of life in youth, and although it has been acknowledged that musical behavior reflects broader psychosocial aspects of adolescent behavior, no measurement instruments have been specifically designed for assessing musical engagement as an indicator of adolescent wellbeing and/or symptomatology. This study was conducted in order to develop and validate a scale for assessing musical engagement as an indicator of proneness for depression in youth. Method Items were developed based on the literature and a prior grounded theory analysis and three surveys (N = 54, N = 187, N = 211) were conducted to select, refine, test, and validate the items. Scale structure was investigated through interitem correlations, exploratory and confirmatory factor analyses (EFA, CFA), and concurrent validity was tested with correlations to depression and wellbeing. Results The final Healthy‐Unhealthy Music Scale (HUMS) consists of 13 items that are divided into Healthy and Unhealthy subscales. Cronbach's alpha coefficients were .78 for Healthy and .83 for Unhealthy. The concurrent validity of the HUMS was confirmed through correlations to wellbeing, happiness and school satisfaction on one hand and depression, rumination, and stress on the other. Conclusions The HUMS is as a promising instrument for screening musical engagement that is indicative of proneness for depression in youth.