The radio broadcasting industry is the oldest form of electronic communication. At the beginning of the twentieth century, radio was purely an experimental medium, as innovators struggled with ways to transmit Morse code via the new wireless technology. Over time, the transmission of dots and dashes would give way to the broadcasting of voice and music. By the conclusion of the twentieth century, radio had developed into a multibil-lion-dollar entertainment and information industry used by individuals around the globe.

Radio is a business, linking advertisers with audiences attracted to a variety of programming formats. Radio has the ability to attract different demographic groups with its programming, making it an ideal medium for advertisers to target different messages. Programming is dominated by music on the FM (frequency modulation) band and by talk and information on the AM (amplitude modulation) band.

The radio industry consists of two distinct...