There is widespread agreement that one-size-fits-all professional development (PD) has limited potential to foster teacher learning and that PD should be ‘responsive’ to the demands of teachers with different profiles. The purpose of this exploratory study was to analyze the PD motivations, needs, and preferences of Singapore primary school music teachers according to their level of specialization in music education. This variable has been relatively unexplored within the field of music-teacher PD. A nationwide survey was run to collect the data. Participants were 286 primary music teachers (about 40% of the entire population), who were split into three groups based on their music education background (Major = 113, Minor = 64, Generalist = 109). Findings indicated that the three groups of teachers had different motivation levels to participate in music-specific PD (e.g., generalists being the least motivated), various needs for further training (e.g., music education majors being the most interested in improving their music content knowledge), and different preferences regarding PD providers and learning formats (e.g., generalists preferring to learn from other fellow colleagues within informal settings). We concluded that the level of specialization in music education plays a major role in determining teachers’ PD motivations, needs, and preferences. This study has the potential to inform the design of more responsive PD initiatives.