Chuck Berry, the rock 'n' roll founder who defined its joy and rebellion in "Johnny B. Goode" and other classics, has died in St. Charles County, Missouri, west of St. Louis. He was 90.

St. Charles county police say they responded to a medical emergency Saturday afternoon and found Berry unresponsive. He could not be revived and was pronounced dead.

Berry hit the Top 10 in 1955 with "Maybellene" and went on to influence generations of musicians. Among his other hits were "Johnny B. Goode" and "Roll Over Beethoven."

Need to know more? Here's an NPR tutorial from last fall around the time of his 90th birthday.