Mar. 30—If there's a more enjoyable form of exercise than ballroom dancing, Joseph Britt hasn't discovered it yet. "It's just one of the most fun ways to be active," he said. Britt, 20, and his dance ...

As two dancers clasp hands and spin across the dance floor, their movements perfectly correlate with a black-and-white video of the same dance being performed nearly 100 years before. Last Saturday, ...