When Louis Armstrong first saw the sheet music for "Hello, Dolly," he was in low spirits. It was just 11 days after the assassination of President John F. Kennedy and Armstrong was in a career lull. He also didn't think much of the song. But he recorded it like the pro he was, and while he was off playing other gigs, it displaced the Beatles as America's top pop song. It also helped Armstrong transition from a jazz pro into a pop-music idol.