An expanded radio dramatization of the original Star Wars trilogy was produced in 1981, 1983, and 1996. The first two radio series, based on Star Wars and The Empire Strikes Back, were produced and broadcast by National Public Radio (NPR) as part of NPR Playhouse. A dramatization of Return of the Jedi was produced by most of the same team and also broadcast on NPR.
The radio serials were made with the full cooperation of George Lucas, who, in exchange for a dollar each, sold the rights to KUSC-FM, the public radio affiliate at his alma mater, the University of Southern California (USC). Lucas also permitted the use of original sound effects and music from the films.
— Wikipedia