This year's box-office Iron Man, Robert Downey Jr., shoots for another kind of ore (Oscar gold) as Steve Lopez, the Los Angeles Times columnist who wrote about Nathaniel Ayers (Jamie Foxx), a musician who developed schizophrenia at Juilliard. Ayers wound up homeless on the streets playing violin and cello solos. Brit director Joe Wright (Atonement) is just the wunderkind to give this story a tough core of intelligence and bruising wit.