‘Once Upon a Time in Harlem’ has its day at the Cannes Film Festival, 50 years after it was shot

David Greaves was 26 when his father, the pioneering filmmaker William Greaves, asked him to be one of four cameramen documenting a historic gathering in Harlem.

In August 1972, William Greaves assembled as many artists, writers, poets, musicians and organizers from the Harlem Renaissance as he could. They came for a cocktail party at Duke Ellington’s Harlem townhouse. There, they talked about the seminal 1920s cultural movement: what they remembered, who not to forget, what it all meant.

“My father would say, ‘Capture the life that’s happening,’” David recalls.

It took more than half a century for the result to see the light of day. But 54 years after that gathering, “Once Upon a Time Harlem” screened this week at the Cannes Film Festival.

No movie in Cannes had a longer road to get here. William Greaves died in 2014 having never finished what he felt would be his most