This dissertation is a study of jazz on American radio. The dissertation's meta-subjects are mediation, classification, and patronage in the presentation of music via distribution channels capable of reaching widespread audiences. The dissertation also addresses questions of race in the representation of jazz on radio. A central claim of the dissertation is that a given direction in jazz radio programming reflects the ideological, aesthetic, and political imperatives of a given broadcasting entity. I further argue that this ideological deployment of jazz can appear as conservative or progressive programming philosophies, and that these tendencies reflect discursive struggles over the identity of jazz. The first chapter, "Jazz on Noncommercial Radio," describes in some detail the current (circa 2013) taxonomy of American jazz radio. The remaining chapters are case studies of different aspects of jazz radio in the United States. Chapter 2, "Jazz is on the Left End of the Dial," presents considerable detail to the way the music is positioned on specific noncommercial stations. Chapter 3, "Duke Ellington and Radio," uses Ellington's multifaceted radio career (1925-1953) as radio bandleader, radio celebrity, and celebrity DJ to examine the medium's shifting relationship with jazz and black American creative ambition. Chapter 4, "Jazz with Ads," uses the mid-1960s to mid-1970s period, in which commercial all-jazz radio had a limited run, as a prism to examine the interwoven roles of genre, format, and commerce in the presentation of jazz on the air.