Malcolm Young, the guitarist who, with his brother Angus, cofounded one of the most massively popular hard rock bands ever, has died at age 64. Young retired from AC/DC in 2014 due to the effects of dementia.

Angus Young announced Malcolm's death in a statement on AC/DC's website.

Today it is with deep heartfelt sadness that AC/DC has to announce the passing of Malcolm Young.
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.
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.

Malcolm Young was one of eight children born to his parents in Scotland. In 1963, the year Malcolm turned ten, the family emigrated to Australia. Ten years later, Malcolm invited his younger brother Angus to join him in a new band called AC/DC, then fronted by singer Dave Evans. Malcolm settled into the role of rhythm guitarist, with Angus taking lead.

Relocating to the UK shortly thereafter, AC/DC — their name inspired by the power supply on a sewing machine — transitioned from an early glam-rock sound to their signature pounding hard rock, Angus unmistakable in his perpetual schoolboy costume. Singer Bon Scott replaced Evans in 1974.

Along with peers like sometime tourmates Black Sabbath, AC/DC became a key influence on the development of the hard rock and metal bands who ruled radio in the 1980s. AC/DC themselves were perhaps the biggest stars among those bands, thanks to the goliath success of their 1980 album Back in Black. Recorded with new singer Brian Johnson after Scott died of alcohol poisoning, Back in Black included songs like "You Shook Me All Night Long" and the title track, and has sold more copies to date than any other album except for Michael Jackson's Thriller.

AC/DC have remained a hugely popular recording and touring unit, and fans were saddened to see the departures of Malcolm Young, drummer Phil Rudd (charged in 2014 with serious criminal activity), and then Johnson, who stopped touring with the band as of last year due to hearing damage. Axl Rose subsequently joined the band, and he and Angus plan to soldier on together.

The band were inducted into the Rock and Roll Hall of Fame in 2003. Reviewing their show last year at the Xcel Energy Center, Peter Diamond wrote that "Whether you like it or not, music like this is simply not being made any more. There are reasons for that, but AC/DC have a rich legacy that they continue to live up to."

In a statement following Malcolm's death, his family wrote, "Renowned for his musical prowess, Malcolm was a songwriter, guitarist, performer, producer and visionary who inspired many. From the outset he knew what he wanted to achieve and, along with his younger brother, took to the world stage giving their all at every show. Nothing less would do for their fans."