The culture of Hollywood and so-called pop music has been on a steady decline for the last couple of decades. Or has accelerated I should say with the thug culture. Madonna was a leader in that.
And she would be three decades ago.
I think pop music culture (think Rolling Stone) was a vector of least resistance for infection of the youthful target.
Bezmenov describes the strategy:
[Yuri Bezmenov: Psychological Warfare Subversion and Control of Western Society (Complete)]
https://freerepublic.com/focus/f-news/3591491/posts
Marcuse illustrates the implementation:
[The Architects of Western Decline: A Study on the Frankfurt School and Cultural Marxism]