During the Cambodian genocide in the 1970s, nearly all of the country’s musicians were killed. But in a strange twist of fate, music saved the life of a Cambodian boy named Sovann. Now a U.S. citizen in Lowell, Mass., he’s trying to make sure Cambodia’s music traditions live on. Across town, a 9-year-old boy seems uniquely gifted to do just that. Explore photos and more