Reminds me of an obscure film called Little Voice that came out some years ago with Michael Caine in it. The underlying message is that the Star is noble and all the people who support her, agents, show biz folks, etc, are scum. The audience is of value only if they recognize the superiority of the Star, and those with refined taste (in other words, who admire the Star) are of intrinsically higher worth than those crude types who fail to recognize her superiority. Just about the most manipulative tripe since The Contender.
What? In reality the movie was written to showcase the actress/singer's talent. At best the plot line was contrived to allow a reason to show her range. When she performs everyone likes her. But she only performs once because she is some sort of nut case. I really don't know where you got the rest of your interpretation of the story. It doesn't square with the movie I saw.
Not arguing with your point about the film's themes, but Jane Horrocks is excellent, one of those talents who for some reason never seem to attract much attention outside the UK.