This year’s Silent Summer Film Festival, running through August 26 with weekly Friday night shows at the Portage Theatre, has focused on the great female stars of the 1920s: Louise Brooks, Gloria Swanson, Mary Pickford, Marion Davies (The Cardboard Lover, Fri 8/19, 8 PM), and Greta Garbo (The Mysterious Lady, Fri 8/26, 8 PM). But screening tonight at 8 PM is the indisputable classic on this year’s schedule: F.W. Murnau’s Sunrise: A Song of Two Humans (1927), starring Janet Gaynor (perhaps best remembered for the original 1937 version of A Star Is Born). Murnau had distinguished himself as one of the great geniuses of the German cinema with such expressionist masterpieces as Nosferatu (1922), The Last Laugh (1924), and Faust (1926). Brought out to Hollywood by movie mogul William Fox and given all the state-of-the-art resources of an American studio, Murnau outdid himself with Sunrise, the tale of a loving couple from the country whose marriage is threatened by a grasping femme fatale from the big city. The clip below is painfully low-res but should give some idea of the filmmaker’s inspired flights of fancy. Imagine this on a big screen in a genuine movie palace, with live organ accompaniment by the skilled Jay Warren; it could be the best picture you see all summer.