Radio broadcasting began in 1920s, and became an instant sensation. People could listen to voice and music transmitted over the air – the stuff of science fiction at that time! Vacuum tube radio receivers were popping up in people’s homes everywhere, and it would not be uncommon for friends, family and neighbors to gather at the home of a person who had one of these amazing new listening machines to revel in this amazing technology. Soon enough, this innovation became mobile, and in the 1930s, we had the first car radios.