Malcolm Young, guitarist and co-founder of AC/DC, died Saturday at the age of 64. Young had been suffering with dementia for the past three years, an illness that forced his retirement from the Rock and Roll Hall of Fame-inducted band he founded with his brother Angus Young in 1973.

“Today it is with deep heartfelt sadness that AC/DC has to announce the passing of Malcolm Young,” AC/DC wrote in a statement.

“Malcolm, along with Angus, was the founder and creator of AC/DC. With enormous dedication and commitment he was the driving force behind the band. 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 had the following to say:

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.

The Young brothers lost their older brother George Young, AC/DC’s longtime producer, in October at the age of 70. In an additional statement, the band said that Malcolm Young died peacefully Saturday with his family by his side.

As rhythm guitarist for the legendary rock band, Malcolm Young served as an indispensable foil to Angus Young’s arena-stuffing riffs. After forming AC/DC in 1973, the Young brothers would be credited as co-writers on every song the band recorded from their 1975 debut High Voltage through 2014’s Rock or Bust. That final album marked AC/DC’s first without Malcolm, who announced in September 2014 that he would permanently leave the band due to dementia.

Megadeth’s Dave Mustaine, who regarded Malcolm as one of rock’s greatest rhythm guitarists, tweeted Saturday following Young’s death:

Read original Rolling Stone article here.