The film being referenced is clearly Psycho, and the story of the singer, her beau and his mother has some interesting parallels to that film.
I love this from the Director's musing:
"The Americans were always good at dying, but not death. Good at plot, but not fatalism. Good at cowboys shot down from the backs of horses, but not the finality of writhing in the dust. Good at the cars roaring lustily into each other as if no one were in them, but not the full horror of a boy hurtling into the rigidity of the steering column. Good at the beautiful Radcliffe heroine succumbing to cancer in her bed, but not the ugly business of the night nurse wiping her clean at two in the morning. What they didn't know is that you take the little glimmer of the truth of death when you see it, and then have the nerve to give it light."Quiet, melancholy and deliberately written.