This two-phased action research project investigates the effects of generalist-specialist teacher collaboration in a Sydney primary school in response to concerns raised in the National Review of School Music Education (2005). The researcher supported and resourced two teachers to teach music to their Stage 2 classes during two terms of 2012. Teacher and student behaviour was observed, to examine the effects of collaboration on the confidence and preparedness of classroom teachers and the musical experiences of students. The findings discuss visible changes in the autonomy and agency of teacher participants, in relation to resource development and sequencing of music lessons. This form of professional development was beneficial in assisting with resourcing, reporting and communicating, indicating the future possibility of further collaborative teaching in this field. Considerations including those of sustainability, teacher identity, interpretation and definitions of ‘meaningful music-making’ are discussed in the future recommendations for music teaching in Australia.