Thank Mura Ziperovitch Dehn(1905-1987), a Russian immigrant schooled in ballet and modern dance, for having the foresight of documenting on film the evolution of African-American vernacular dance. Starting in the early 1930s, Dehn made it her mission to film the various styles of black dance beginning at the turn of the century (recreated for her camera by Savoy dancers), cataloging its evolution up to 1986. The result is a magical 5-hour documentary for those who want to "keep it real" on the dance floor and for those who want to use it as a springboard for their own original choreography.
The 10-minute clip above is from that remarkable documentary called The Spirit Moves: A History of Black Social Dance on Film, 1900-1986. Divided into three parts, Part 1, Chapter 3's "Savoy Routines" uses famous dancers from the 30's era Savoy Ballroom to demonstrate the moves. Because of technical limitations back then, sound was added later (matching the musical style but not necessarily the actual songs the dancers were dancing to).