Dirty Harry recommends the below clip of the Nicholas Brothers as the greatest dance number ever put on film, and no other than Fred Astaire concurred. Click on it and be impressed.

One of the main criticisms of Black dancers in the thirties and forties was that they didn't have the discipline to submerge the individualism into a whole of a choreographed routine. Click on this one, a scene from a Gene Kelly movie, where Kelly proved that the Nicholas brothers could "fit" and immerse themselves into a choreographed whole. Enjoy.