This paper has reported the results from the case study component of a larger study designed to explore the knowledge, beliefs and practices of primary school teachers about the integration of mathematics and music. An in-depth case study of a primary school teacher who reported practising the integration of mathematics and music helped provide information pertaining to how a teacher plans, programs and implements instruction involving the integration of mathematics and music. The findings of this study not only provide a practical model of the integration of mathematics and music in the classroom, they also assist in understanding a range of issues and concerns surrounding the implementation of teaching approaches involving subject integration.