We think of It's a Wonderful Life as a great American movie, a great Jimmy Stewart movie, a great Frank Capra movie — and, of course, as a great Christmas movie. We don't think of it as a great Italian-American movie. But we should, especially at Christmastime, when Italian-Americans — of Capra's generation and beyond — can be heard in every shop and restaurant singing many of the songs that define the season. Capra was born in Sicily, and at age 6 moved to Los Angeles. It's a Wonderful Life is spiced with subtle but significant references to his fellow...