When he cut Smokestack Lightnin' at Chess Records, it sounded more dangerous than anything released since. Killing Floor. Spoonful. Back Door Man. Willie Dixon wrote the words, but Wolf made them sound like threats. His guitarist Hubert Sumlin played jagged, angular solos. The Stones begged to open for him on TV. Wolf agreed, then made sure they remembered who the headliner was.

He drove a tractor in the day and played juke joints at night. Underneath the menace was a man who paid his band a salary, gave them health insurance, and made them show up sober -- revolutionary things in the 1950s Chicago blues scene. He died at 65 from complications of kidney surgery. They called him the Wolf. Nobody argued.

The Wolf outlasted his rivals, his imitators, and the British kids who copied his songs without paying. He was the most terrifying performer in blues and one of its most principled men. Smokestack Lightnin' still sounds like a freight train coming through your living room.