Harlem Renaissance documentary Once Upon a Time in Harlem has been selected as the winner of the Library of Congress Lavine/Ken Burns Prize for Film. The film documents a 1972 cocktail party inside Duke Ellington’s townhouse shot by William Greaves, who invited every surviving creator of the Harlem Renaissance that he could locate and filmed what happened as they reminisced, argued and explored how culture survives across generations. The film was finished and restored, 50 years later, by William Greaves’ son David Greaves. Once Upon a Time in Harlem will receive a $200,000 prize as part of the film award providing recognition and…