For a brief moment in the early 20th century, Charlie Chaplin had the world’s most famous face. His “tramp” character is familiar even to those who haven’t heard of The Gold Rush or City Lights. But for all Chaplin’s ubiquity, Buster Keaton is the silent film star whose face leaves a stronger impression: It’s always frozen, even when his characters are in grave, real-life danger. Keaton made several great movies during his heyday, yet his masterpiece is The General, a racing comedy about a young Confederate railway engineer who gets involved in an unlikely chase between Union forces on the train tracks. It all culminates in impressive (for 1926) special effects and stunts, including the full-scale destruction of a bridge while a train passes over it. This proto-action spectacular is always worth celebrating, particularly when the National Gallery has a newly restored print and members of the National Symphony Orchestra to provide live musical accompaniment. The film shows at 6:30 p.m. at the National Gallery of Art East Building Auditorium, 6th Street and Constitution Avenue NW. Free. (202) 737-4215.