A decade after his death, genre-defying director William Greaves has one last trick up his sleeve: never-before-seen footage he considered the most important he ever filmed. At a 1972 cocktail party he masterminded for living luminaries of the Harlem Renaissance, Greaves searches for the divine origins of his own creativity. Shot on 16mm, newly restored and directed by his son David, Once Upon a Time in Harlem is both a self-exploration and an inquiry into the role of the artist, the value of art in society, and the creative force behind the Harlem Renaissance.