Psychological safety (PS), defined as a shared belief that an environment is safe for interpersonal risk-taking (e.g., admitting to mistakes, asking for help), is increasingly recognized as critical to learning and performance and has been thoroughly researched in high-stakes fields (e.g., business, education, healthcare, sports). This construct is, however, yet to be investigated in specialist music performance training (SMPT). Based on theory and previous cross-field research, this study examined the antecedents and outcomes of PS in one-to-one music lessons. A total of 358 music performance students from 12 conservatories and specialist music schools in the United Kingdom completed a survey that included an adapted version of Edmondson’s (1999) PS scale. Firstly, the scale’s psychometric properties were examined and found to be appropriate for this study’s sample. Covariance-based structural equation modeling showed that teachers’ leadership and supportive behaviors positively predicted PS, which in turn directly and indirectly influenced learning and performance-related outcomes. Although the cross-sectional design precludes causal inferences, this study deepens our understanding of the psychosocial factors associated with high-performing musicians’ environments and how they may foster desirable results. To the authors’ knowledge, this is the first study to investigate the construct of PS in SMPT.