Bob Mackie, who died Monday at eighty-seven, spent more than half a century doing something rarer than designing clothes — he gave the women of Hollywood and the pop stage a visual language for their own power. His beaded, sequined, architecturally precise gowns were not merely garments but declarations, collaborations between a designer's vision and a performer's presence. With his passing, the possibility of new such alchemy closes, even as the photographs, the gowns, and the influence he seeded in generations of designers endure.