
FM radio allowed several audiences to be addressed at once. Prior to the radio, it was impossible for information to be broadcasted instantly, or arguably more important for one to be able to listen to the radio while doing something else. Men could listen in on the news on their ways to work and the women at home could tune into the shows they enjoy, both without having to stop whatever it is they were busy with. This was not even concievable before the radio, but Marconi and David Sarnoff's visions shaped Mainstream America to make the impossible... possible.
Radio got to the point where it was almost in every household, but then another technological revolution occured, the television. Coincidentally, radio always found a way to keep it's flare. Around the same time television became big, the era of DJs and music on the radio began. Even today, with computers and i-Pods making music so much more personal to the individual, Satellite radio became very popular, offering hundreds of stations that allowed the individual to select very specific stations that played one particular genre/type of music. The internet Pandora, seems to be offering radio a threat now, but radio has survived a lot of change thus far... I'm sure it will be around for a while.