The brothers are graceful evidence of how immigrants from the former Soviet Union and the Soviet-bloc lands are infusing new life into ballroom dancing. A telling result is that in New York, New Jersey and Connecticut, immigrants from the former Soviet Union now own 11 of the 23 Fred Astaire dance studios, the chain of franchises Astaire founded in 1947. And there are an additional hundred or so Russians who teach in the 89 other Astaire studios around the country.