AC/DC co-founder and ex-guitarist Malcolm Young has died aged 64, his publicist has announced.
Young found the Australian rock group alongside his brother in 1973, with the band going on to sell more than 200 million records worldwide.
The Scottish-born musician left the group in 2014 after it was revealed he was suffering from dementia.
A statement on AC/DC's website on Saturday said it was "with deep heartfelt sadness" that they had to break the news of Young's death.
It added that Young had died "peacefully" with family at his bedside.
The statement described Young as the "driving force" behind the band.
"With enormous dedication and commitment he was the driving force behind the band," it read.
"As a guitarist, songwriter and visionary he was a perfectionist and a unique man.
"He always stuck to his guns and did and said exactly what he wanted. He took great pride in all that he endeavored. His loyalty to the fans was unsurpassed."
Angus Young added: "As his brother it is hard to express in words what he has meant to me during my life, the bond we had was unique and very special.
"He leaves behind an enormous legacy that will live on forever. Malcolm, job well done."
In an update, the band wrote: "Malcolm had been suffering from Dementia for several years and passed away peacefully with his family by his bedside."
Music stars such as Scottish band Biffy Clyro and American punk band Dropkick Murphys paid tribute to the star on Twitter.
Young is survived by a wife, two children and three grandchildren.