This design case describes how the principles of Universal Design for Learning (UDL) informed the development of SpectrumPlay, a digital tool created to support learning and instruction of elementary music literacy and composition in inclusive music classrooms. The learning supports embedded in the tool enable students with visual processing difficulties learn to read music notation and play independently. Informed by Universal Design for Learning and Cognitive Load Theory, SpectrumPlay emerged as a direct response to the needs of diverse students. The tool evolved from a paper prototype that supported independent learning to a digital software that accounts for individual learner needs. In this design case, design judgments and prototype iterations provide precedent to the learning technologies design community for transforming an inclusive instructional design strategy into a digital tool with broad transformational reach.