TeachersPayTeachers.com is an online marketplace where sellers offer learning activities, lesson plans, decorations, and related materials for use in school classrooms. The marketplace includes thousands of music education materials that are used by teachers throughout the United States. The purpose of this study was to explore the content of what is sold, who is selling materials on the platform, and the quality of the music activities. Our analysis of the 500 most-rated music items indicates that sellers are primarily marketing activities, classroom materials, and decorations on the platform. Despite listings from 91 different sellers, a small number of active "teacherpreneurs" were responsible for most of the materials. Our analysis of the quality of the top 50 activities shows that materials are generally aesthetically pleasing and clear in purpose, yet may may not promote authentic pedagogical practices in music education. The scope of resources available combined with the level of adoption shows that this platform has the potential to elevate worksheets and notational activities to the same level as meaningful musical engagements. We discuss findings in relation to curriculum development, teacher agency, and the potential for TpT and similar platforms to impact how music educators curate curriculum resources for use in their classrooms.