The image of John Travolta in a white disco suit has so saturated popular culture that uninitiated filmgoers tend to think of Saturday Night Fever as a goofy, dated disco cash-in. But those who've seen the film know it as a rich slice of Italian-American life in Brooklyn, topped with post-Scorsese '70s grit and filled with a surprising amount of ugliness. Travolta's working-class disco enthusiast spouts racist slurs, treats women badly, and is as dim and clumsy off the dance floor as he is rapturous on it. He and his friends knock around the streets and nightclubs of their Bay Bridge neighborhood, working crummy jobs all week so they can afford to buy pills and booze and pay cover charges on the weekend. Saturday Night Fever's plot revolves around a dance contestand Travolta's attempt to get pretty, seemingly classy Karen Lynn Gorney to be his partnerbut its story is about the tyranny of family and friends, in a cramped urban grid just across the river from a sprawling center of wealth and glamour. "There are ways of killing yourself without killing yourself," Travolta mutters at one point, bucking against a way of life that'll probably leave him as a lifer at a paint store, married to some shrill woman he'll impregnate in the back of a car. What saves Saturday Night Fever from being unrelentingly bleak (even for the cinema of the '70s, when homely faces and desperate lives weren't necessarily box-office poison) is Travolta's appealing balance of softness and sharpness, and the sheer physicality of the disco dancing. Director John Badham employs a variety of extreme angles in the dance sequences, suggesting the lightly masked sexuality and violence beneath the dancers' poses. Out of the nightclubs, Badham makes masterful use of steadicam (then a fairly new device) to track through the cluttered anxiety of homes and workspaces on the way to the wide-open harmoniousness of the dance floor. Badham's DVD commentary is livelier and better organized than such tracks usually are, full of trivia and affably delivered inside information. His storytelling exuberance explains why people still think of Saturday Night Fever as escapist fun. It is, in a way, but it's also harrowingly clear about what's being escaped.