Celine Dion comparisons are too huge to mean a damn thing, but only huge will do. Hill's singing is more "human-scale"--like the female CEO of a Birmingham-based health-maintenance operation. Her drumming rocks--like RoboCop on steroids. She's an SUV that seats five linebackers across, a radio signal that grinds the competition into static, the megabomb they'll drop on anybody who doesn't get liberated on their timetable. At this horrible moment in history, she's American overkill as popular music. One thing you can say for Dion--she's Canadian. C