Fans of Vera Farmiga really need to check out Joshua (2007), a psychological thriller that blends sociopathy and sibling rivalry in a Freudian cocktail so potent that after the film ended, it started a semi-heated debate in our house about what antisocial personality disorder actually is.
Farmiga plays Joshua's mom, Abby Cairn, who begins a prolonged and virtuosic mental unraveling almost from the moment the film begins. Sam Rockwell plays her husband, Brad, a likable but subtly smug Wall Street type too content with his life to notice the first several rounds of its progressive implosion.
In one brilliant sequence, Brad's walking home from work, ear buds in and singing along to the sweetly upbeat "See the World" by Gomez. He's still jamming good naturedly along as he steps through the door of their Manhattan apartment at which point Abby rushes abruptly up to him, looking miserable and clutching their crying newborn. We can't hear what she's saying because Ratliff keeps the music turned up (Brad's earbuds are still in), but her despair is all the more apparent against the feel-good Starbucks rock. The contrast highlights what different days these two people are having -- how differently they see the world at this point. A great little touch.
For another film that explores escalating childhood sadism and uses music brilliantly, see Lynn Ramsay's brilliant We Need to Talk About Kevin.