No one packed more passion into disco than Donna Summer—her catalog represents a perfect marriage of irresistible grooves and unstoppable feelings. “On the Radio” is part ballad, part quick-stepping attempt to dance the heartbreak away; “Love to Love You Baby,” with its slow-burning bassline and whispered vocals, is desire incarnate. And while “Last Dance” and “Hot Stuff” raise the roof with rousing horns and soaring choruses, the Giorgio Moroder-produced “I Feel Love” is a minimalist slice of body-moving bliss.