Aligned with the global mandate of SDG4 (Quality Education), this study contributes to the sustainability of the music education workforce by looking at the psychological transition of conservatory-educated undergraduate students to the teaching profession. As far as technical quality is concerned, Beijing’s conservatory students are good, but they remain vulnerable to “theory-practice disjuncture” in teaching over the longer term. This study examines the predictive power of teaching self-efficacy and occupational emotions for professional identity and, in turn, how professional identity predicts career intention. Using a convergent mixed-methods design, this paper combines quantitative data from 250 final-year music education majors with qualitative data from the narratives of 20 semi-structured interviews. The quantitative results show that self-efficacy (beta = .508), and emotions account for professional identity which fully mediated emotional experience and career intention (beta = .351). Qualitative findings highlight systemic factors such as “mentorship validation” and “theory-practice disjuncture” that affect this sustainability pipeline. It is important to foster a strong professional identity to provide a resilient teaching force in Society 5.0. Recommendations for curriculum reengineering and emotional scaffolding are offered to take music talent into account, to have a sustained social impact and educational sustainability.