Johnnie Clyde Johnson

One of the most important figures in the history of Rock 'n Roll has died at the age of 80.

Keith Richards, the Rolling Stones guitarist who was featured in the documentary, became one of Mr. Johnson's chief supporters. "You can tell how much Johnnie's blues stylings had to do with the music for Chuck's tunes," he once said, "by the fact that a lot of those characteristic Chuck Berry guitar riffs and compositions are in keys familiar to Johnnie and other pianists but seldom used by guitarists."

In 2000, Mr. Johnson sued for co-writing credit on 57 songs, claiming Berry had taken advantage of Mr. Johnson's alcoholism to claim sole credit. A federal judge dismissed the claim because too many years had passed since the disputed songs were written.

Mr. Johnson's final fight was winning recognition from the Rock and Roll Hall of Fame, which inducted him in 2001, when it added a new category for sidemen. Mr. Johnson saw the long wait as one of rules and politics, saying, "I knew there were others in there not as good as me."

Geez, that's an understatement for the ages.