That would be the art culture. I know culture is a way of life.
Culture and US are often mutually exclusive.
The owners are the makers, presenters, and buyers: a mix of the museums, galleries, dealers, critics, patrons, collectors, charitable foundations, universities and other arts colleges and the artists themselves. Plus there's an influence that derives from government policy well hidden behind the scenes, paying for critics and curators to take desirable directions.
But guess what?
The US has extended cultural hegemony of its arts across most of the western world for at least the last 65 years.
Rich people.
revising my answer
Culture is an incredibly broad topic.
It includes the popular as well as the elite; the sensationalist and the subtle; the entertaining and the meaningful; the gimmicky and the deep; the "aaah! :)," "ah-ha!," and the "what's that?" moments.
But by and large it's the rich that control it - and behind that is a support for the dominant paradigm.
The West promotes the idea of freedom of expression in the arts, but when you get down close and really examine it, the freedom is in several ways limited by who gets selected for success.
What is your answer to your own question?