Briefly describe one specific historical similarity between mass media in the 1920s and in the 1950s

The 1920s saw the rise of the Radio turn into a source for a mainstream media and became popular all over the world.

They became instant sources of news, information, entertainment, wars, and advertisements. At that time, Radio was seen as the pinnacle of human communication technologies that had brought the world closer.

By the 1950s, TV had replaced radio, as the most important source of information.

Both mediums ushered in the growth of mass media and instant communication. One did it with sound, while the other did it with a combination of sound and video.