The literature concerning pre-service training in music education for generalist primary or elementary school teachers reveals a long-standing problem for teacher educators: low or poor self-efficacy concerning the teaching of classroom music. Concurrently, a critical examination of training programmes has less often featured, with only limited discussion of digital approaches to classroom music-making constituting the focus of empirical research. Through a focused case study in one Australian university, 136 pre-service teachers participated in a face-to-face module of interactive music education which culminated in a peer-directed collaborative digital music-making project. Pre- and post-surveys were implemented with shifts in pre-service teachers' self-efficacy measured according to Bandura's self-efficacy scales. Legitimation Code Theory from the sociology of education then served as an overarching theoretical lens through which to appraise the findings. Despite an enduring self-concept as 'non-musicians', the results highlight positive shifts in self-efficacy through the utilisation of peer-directed digital music-making tasks, with implications for teacher training programmes more broadly situated.