Entertainment has always been a part of socialization. Learning social cues, acceptable behavior, unacceptable responses, biases, values, etc. That's a natural role from cave man days on up. The propaganda uses of this are pretty obvious, but what's *less* so (And probably more valuable in the long run) is the indoctrination value.
When the Romans took over a new town, the first thing they did after their holding was secure was to build a theater. It wasn't for the "Rah Rah Rome is Great" thing, or the "Resistance is Futile," both of which were pretty self-evident since they'd just *captured* the town or city or province or whatever. Nope: the reason they did it was because entertainment provides a means of easily indoctrinating - integrating - people into a larger society.
In the same way we domesticate dogs by plugging ourselves into their social order as the alpha, so the Romans were able to domesticate most of the Med most of the time by plugging their entertainment into the social order. A person who entertains you is a person to whom you're listening. A person who's cool is someone you'll emulate, be they fictional or not. When the Church began to consolidate the western peoples outside the empire, they made a very conscious decision to tell stories that weren't overtly pagan or Christian, but were just stories which emphasized the values of the local group, and maybe nudged in some new values in the margins. The oldest story in our language - Beowulf - is an example of this. It's a straight-ahead Germanic adventure story that never overtly mentions the Judeo/Christian God, nor does it ever overtly diss Woden or Thonor. A casual listener of either faith would think it's about one of theirs. Jesus never makes an appearance, nor anything preachy, and yet: it sneaks in the great flood and several other things in the form of a monster story. How many other stories were floating around written to the same purpose, or altered to fit it? Scores? So you come in a pagan, enjoy an hour or two in the meadhall, and go out still a pagan, but slightly less so. And don't even get me started on "The Cathode Ray Mission."
It's really frackin' cool, when you think about it!
This is a natural human process. You can't stop it. You can control it somewhat for good or for ill, or you can ignore it and let it run wild, but entertainment has always been used for social bonding, and it always will be. You can't have a really coherent society without it.
Generally speaking, people try to drive the stuff they see as important, one over the other. Church/Pagan, Roman/Barbarian, Mayberry RFD/Starsky and Hutch, whatever. Generally speaking, they tend to ignore stuff they don't see as being important until it's way too late: Elvis, Jazz, Music in general, Science Fiction, technology, the new wave of any art you wanna' choose, fashion, urban legends.
Yes, "They" control the vertical and the horizontal - and they (or someone just like 'em) always have and always will (Sometimes for the greater good, sometimes not), *BUT* the really interesting stuff always happens when nobody's looking.