These days we take for granted the wide variety of music available on the radio.
But, this wasn't always the case. In the early days of radio, stations were capable of broadcasting only a narrow range of sounds, which was all right for the human voice but music didn't sound very good. There was also a great deal of crackling and other static noises that further interfered with the quality of the sound. A man named Edwin Armstrong, who was a music lover, set out to change this. He invented FM radio, a technology that allowed stations to send a broad range of frequencies that greatly improved the quality of the music. Now, you'd think that this would have made him a millionaire; it didn't. Radio stations at that time had invested enormous amounts of money in the old technology. So the last thing they wanted was to invest millions more in the new technology. Nor did they want to have to compete with other radio stations that had a superior sound and could put them out of business.