Chuck Berry, whose rollicking songs, springy guitar riffs and onstage duck walk defined rock & roll during its early years and for decades to come, died on Saturday. The St. Charles County Police Department confirmed the news on Facebook. Berry was 90 years old. "Chuck Berry was rock's greatest practitioner, guitarist, and the greatest pure rock & roll writer who ever lived," Bruce Springsteen wrote on Twitter, while Brian Wilson wrote, "I am so sad to hear about Chuck Berry passing - a big inspiration! He will be missed by everyone who loves Rock & Roll. Love & Mercy."