This study analyses responses (n = 309, across 94 schools) to the General Self-Efficacy Scale (Zhang and Schwarzer [1995]. "Measuring Optimistic Self-Beliefs: A Chinese Adaptation of the General Self-Efficacy Scale." Psychologia: An International Journal of Psychology in the Orient 38 (3): 174-181) from Hong Kong primary teachers of inclusive music classes. Analysis of these results sheds light on the impact that contextual reforms have on these non-core subject music teachers' practice. Respondents' perceived self-efficacy is moderate - characterised as a see-saw relationship between their personal and external domains. A possible behavioural intervention suggests professional-sharing being further enriched were current Education Bureau's in-service SEN courses to be inclusive of all primary school subjects, including music. Specific factors that underpin these respondents 'moderate' self-efficacy are identified as forming two clusters, human resource management and stress, with possible behavioural interventions for these being outlined. [Copyright of Music Education Research is the property of Routledge.]