MUSIC royalty Malcolm Young, the Australian guitarist and AC/DC co-founder, has died aged 64.

Known for the powerhouse riffs and rhythm guitar that propelled the Sydney group to superstardom, Young had been suffering from dementia for at least the past three years.

He died peacefully on Saturday with his family by his bedside, a statement said.

“With enormous dedication and commitment he was the driving force behind the band,” AC/DC said on its website.

“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.”

Younger brother Angus said the pair were close until the end.

“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 said.

“He leaves behind an enormous legacy that will live on forever.”

Malcolm was replaced by nephew Stevie for the band’s last tour promoting the 2014 album Rock Or Bust. He wanted the band to continue the tour.

“Mal always wanted the music to go on,” singer Brian Johnson told Rolling Stone in 2014. “And I’m not going to say no.”

Rip Malcolm, you will be missed, thanks for the greatest rock and roll ever #ACDC #malcolmyoung pic.twitter.com/g6EjgqJ5Zr — Brian Morton (@brianthemorton) November 18, 2017

According to Angus Young, Malcolm started battling symptoms of dementia before they made their 2008 album Black Ice, but he was “still capable of knowing what he wanted to do”.

“I had said to him, ‘Do you want to go through with what we’re doing?’ And he said, ‘Sh*t, yeah.’”

Malcolm started getting treatment during his last tour with the band from 2008 to 2010 and during which he had to relearn the very riffs he’d come up with.

It was strange for him, Angus told Rolling Stone, “but he was always a confident guy, and we made it work”.

“Renowned for his musical prowess, Malcolm was a songwriter, guitarist, performer, producer and visionary who inspired many,” the statement read.

“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.”

Young founded AC/DC in November 1973 and soon asked Angus to join when they were 20 and 18 years old respectively.

They began national touring in 1974 with singer Dave Evans

Malcolm is survived by his wife O’Linda and two children.

His death comes just weeks after his brother George Young, guitarist for the Easybeats and AC/DC producer, died at age 70.

Tributes started pouring in from around the world, both from the music industry and elsewhere.

RIP Malcolm Young

Legend.

He was the founding member of AC/DC & the engine that roared behind the most powerful band in the world.

He wrote Back In Black, Highway to Hell, You Shook Me All Night Long, Highway to Hell, so many songs...

Travel safely to the stars, Malcolm.

Legend. pic.twitter.com/xfjylBbh4u — Ryan Adams (@TheRyanAdams) November 18, 2017

'Malcom Young the best right hand in game! RIP. Play AC/DC loud all day!' KJ @acdc — stereophonics (@stereophonics) November 18, 2017

It is a sad day in rock and roll. Malcolm Young was my friend and the heart and soul of AC/DC. I had some of the best times of my life with him on our 1984 European tour. He will be missed and my deepest condolences to his family, bandmates and friends. — Eddie Van Halen (@eddievanhalen) November 18, 2017

The driving engine of AC/DC has died.A tragic end for a sometimes unsung icon. One of the true greats. RIP. https://t.co/cJe1Xr17IA — Paul Stanley (@PaulStanleyLive) November 18, 2017

RIP Malcolm Young. Your guitar playing was a huge inspiration. Thanks for that #malcolmyoung #ACDC — Bryan Adams (@bryanadams) November 18, 2017

We are deeply saddened to have heard the news of the passing of Malcolm Young from AC/DC. Malcolm was the heart and soul of AC/DC and as fine an example as any to rhythm guitarists everywhere. Rock In Peace, Malcolm. Hope we see you up there. Love Dropkick Murphys pic.twitter.com/qCWxmjmKEQ — Dropkick Murphys (@DropkickMurphys) November 18, 2017

Our Thoughts & Prayers Are With His Family, Friends & Fans...Great Guy ...A Pleasure To Know...Truly Missed, Malcolm...XX https://t.co/1ECM7urBN8 — David Coverdale (@davidcoverdale) November 18, 2017

While most of the world goes on with the day, many of us are mourning the loss of the great #malcolmyoung . I can’t tell you how much joy he and @acdc have brought me. This is a legend, a real legend.lets all remember him not just today but every day 💜 Mal Rules!! pic.twitter.com/22vGOLfKBz — Charlie Benante (@skisum) November 18, 2017