Elon Musk visited the National Security Agency on Wednesday, current and former U.S. officials said, meeting with leadership a week after saying the intelligence and cybersecurity outfit needed an overhaul.

Mr. Musk is fundamentally a creature of Silicon Valley, a scene that initiated an entire revolution in power dressing. The young masters of that universe dressed down to show that they were members of a new elite — one that refused to dress like the grown-ups they were about to topple. It was the defeat of the suit by the T-shirt.