'That Mysterious Rag': Vaudeville, Tin Pan Alley, and the Rise of the American Entertainment IndustryThe musical style known as Ragtime exploded into mass popularity at the turn of the 20th century. First performed by Black artists in Missouri and New York, it was quickly taken up by performers and audiences across the United States. Historical accounts of Ragtime have typically fallen into two camps: they either provide in-depth analyses of the musical innovations of the form’s principal innovators, or they are broader cultural examinations of the gender and racial politics at the core of the style’s appeal. However, far less attention has been paid to Ragtime’s integral relationship to the evolution of America’s entertainment industries, most notably, the intertwined development of Vaudeville and Tin Pan Alley. Over the final decades of the 19th century, Vaudeville had evolved into a centralized, bureaucratically ordered form dominated by corporate syndicates that controlled theaters in hundreds of cities across the country. Over the same period, music publishing had shifted towards a new national audience, as increasingly ambitious firms worked to generate mass demand for their high-turnover products. These two industries, both based in New York, were naturally complementary—Vaudeville needed a constant flow of new material, and Tin Pan Alley required performers to introduce their products to crowds throughout the nation. Ragtime was the first form to benefit from this potent interaction. Using newspapers, corporate records, personal accounts, and performer archives, this paper reconceptualizes Ragtime as the inaugural product of this emergent mass-entertainment complex, examining the business practices that helped propel the boundary-pushing style to the forefront of American music. In doing so, it reveals the critical importance of the rarely-analyzed linkages between popular theater and commercial publishing in the early 20th century.