From the Media Access Project:
In 1945, the Supreme Court declared that "the widest possible dissemination of information from diverse and antagonistic sources is essential to the welfare of the public, that a free press is a condition of a free society." As the federal agency charged with regulating the mass media, the Federal Communications Commission (FCC) has long had rules in place to promote "the widest possible dissemination of information from diverse and antagonistic sources."
Over the years, however, many of the rules designed to foster production of independent news and entertainment have been weakened. Today, only a limited number of rules remain that prevent any person or company from owning all of the media outlets in a small or medium sized city or from owning media outlets that blanket the country. Already Congress has virtually eliminated the rules restricting radio ownership to allow a single company, Clear Channel, to own radio stations in every market and own the majority, if not all of the radio stations in any single market. This lets Clear Channel select music based on whether artists pay Clear Channel promotional fees or whether Clear Channel agrees with their politics or message. Clear Channel’s cost saving measures and "efficiencies" have virtually eliminated local music and local news, relying on national play-lists, centralized news services, and technology that allows central programmers to add local "color" at delivery. Clear Channel also determines which talk show hosts get syndicated on its stations, ensuring carriage of one point of view in every market to the virtual exclusion of all others.