Older generation: How many parent companies were there that controlled the media decades ago compared to now?

There are now only 5 companies that control all the networks out there (everything on TV): GE, Time Warner, Walt Disney, Viacom, News Corp.





How many companies were there before all the mergers and buyouts?Older generation: How many parent companies were there that controlled the media decades ago compared to now?
There were 37. Don't know why the government allowed it but they did.