On BoingBoing there is a link to this “hypnotic folk dance,” which only one commentator identified correctly as Nadia Nadezhdin’s ensemble Birch founded in 1948. (Thanks, Terry di Paolo!) However, it is worth pointing out that the name of this particular piece, Прялица, means “spinning jenny,” as in spinning of thread for weaving cloth. This should be obvious from the motions of the performers as they sit and twist the braids of the thread, and is reinforced by the threads strung over the stage, and the camera angles taken through the skein of strings. If you watch closely, you will also note that the patterns of the rotating group (when viewed from above) actually resembles different aspects of the spinning wheel, a technology that was much closer to the ordinary Soviet citizen of the 50s (when this dance was most likely performed).
Other internal evidence to date this piece can be seen in the fascinating crowd scenes at the end of the performance. The giant klieg lights have fine molded vents and precision external gears. It’s rather difficult to guess at a date of manufacture, but they clearly look like post WWII, pre 1970s objects. But the image of these technical workers at the controls of great lights is a wonderful tribute to the socialist realism of the original futurists, a pure homage to Rodchenko, if you ask me!