Fayard and Harold Nicholas were a fantastic set of flash-dancers who performed as the Nicholas Brothers. Born seven years apart, the brothers performed for decades on stage and screen, later teaching dance to Michael and Janet Jackson, among many others. In the performance below from Stormy Weather, many of their trademark moves are on display -- jumping down stairs into splits, sliding up from splits without using hands, and gleefully jumping through orchestra stands, while tap-dancing in unison. This is downright amazing. According to The Kid Should See This:

Fred Astaire once called this performance “the greatest dance number ever filmed.” Mikhail Baryshnikov said, “Those guys are perfect examples of pure genius.”

Word. Are you ready for this?

Yes, that's Cab Calloway at the beginning, and his big band they're dancing among. For more context (and a slightly clearer video), check out this longer version with more of Calloway at the beginning: