Malcolm Young, AC/DC’s guitarist and songwriter, died on Saturday at 64. His family confirmed in a statement that Young had died and added that he had been suffering from dementia for several years. They did not reveal where he died. He was born on January 6, 2953, in Glasgow, Scotland, but was later emigrated to Sydney, Australia.

Young helped found the Australian rock band with his brother Angus Young and they played their debut show of AC/DC at club in Sydney on New Year’s Eve in 1973. The band was inducted into the Rock & Roll Hall of Fame in 2003. “AC/DC’s music and approach has a worn-in, scruffy vibe that stood in the stark contrast to the pretentiousness suffusing much rock music at the time,” the Hall of Fame website said.

The group is known for its power riffs, loud vocals and boundless energy, found enduring popularity and great commercial success.  The band won its first Grammy in 2010, for best hard rock performance, with the song “War Machine.” The band’s album Back In Black was inducted into the Grammy Hall of Fame in 2013.

Young’s last performance with the band was in 2010 in Balbao, Spain. Rolling Stone said at the time, he was having cognitive problems but decided to continue to perform during the tour, which he had to oftentimes relearn guitar parts that he had written. Stevie Young, his nephew, replaced his uncle in 2014.

Friends and fans of Young shared memories they had on social media on Saturday. Eddie Van Halen, the guitarist, tweeted, “I had some of the best times of my life with him on our 1984 European tour.” Ben Jolliffe, a member of the band Young Guns, tweeted, “Absolutely broken to hear of Malcolm Young passing. Grew up with the family and he was like a second dad to me.”

The band posted a tribute to Young on their website and social media, calling him “the driving force” behind their success. The statement said, “As a guitarist, songwriter and visionary has was a perfectionist and a unique man. He always stuck to his guns and did and said exactly what he wanted.”