We present and describe one of the components of our mathematical musician platform, Play My Math, called the Course Creator Tool. Teachers can use this tool to integrate music in their pedagogy and create cross-curricular (i.e., music and mathematics) lesson plans. The current version of our Course Creator Tool works with eight modules (i.e., Description Block, Multimedia Block, Music Lab, Beat Maker, Fraction Lab, Music Generator, Fraction Generator suite, and Worksheet Demonstrator) that the teachers can freely organize and customize for their lessons. We have also created templates they can copy and modify to cover 17 subtopics of fractions. The need for a Course Creator Tool was derived from feedback given by teachers during a study we did in Mexico during the first quarter of 2024, and from UK teachers’ feedback coming from an intervention done during the first quarter of 2025. By closely collaborating with teachers in our design-based research iterations, we aim to increase the educational value of the Play My Math platform, empower mathematics teachers’ practice, facilitate musical integration into mathematics pedagogy, and ultimately progress towards a mathematical musician curriculum for K–12 education.