If you go to the Charles to see "Cabin in the Sky" tonight at 7 or Thursday night at 9 as a tribute to the late Lena Horne (that's her in a 1940s studio shot, below), you'll be savoring one of the great American movie musicals. With Horne as sassy, midriff-baring Georgia Brown (a virtuoso of temptation), Eddie "Rochester" Anderson as Little Joe (there's nothing small about his libido) and Ethel Waters as his wife and salvation Petunia (the great, soulful Waters makes holding a torch for a man an eternal light), the film has a comic triangle to die for. It also has a score to kill for, including "Taking a Chance on Love" and "Happiness is a Thing Called Joe." Astonishingly, it was Vincente Minnelli's debut movie. The director who went on to make "Meet Me in St. Louis" and "The Band Wagon" was already a master of movement and sound-stage choreography. Everything in the film is touched with wit, including the way the commanders of imps and angels are dressed like competing drum majors -- or the way Lucifer, Jr.'s idea men carry on like low-comic versions of MGM executives at a story conference. You get only a frustrating smidgen of Louis Armstrong, but Duke Ellington and his Orchestra are a blast, and so is the dancing of John Bubbles. And the film has one of the best examples of re-purposing in movie musical history: a guest appearance from the tornado in "The Wizard of Oz." The film will blow you away.