AC/DC guitarist Malcolm Young has died aged 64 after suffering for several years with dementia, the band announced Saturday.
Young founded the Australian rock group with his brother Angus, who said he will leave "an enormous legacy".
"Today it is with deep heartfelt sadness that AC/DC has to announce the passing of Malcolm Young," a statement on the band's website said.
"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."
Best known for their hit song Highway to Hell, AC/DC formed in 1973 and went on to produce 17 studio albums, selling more than 200 million records.
Friends and musicians paid tribute to him on Twitter.
Black Sabbath singer Ozzy Osborne tweeted: "So sad to learn of the passing of yet another friend, Malcolm Young. He will be sadly missed. God Bless."
Def Leppard frontman Joe Elliot called him "an incredible guitar player & the glue for that band onstage & off."
Eddie Van Halen wrote: "It is a sad day in rock and roll. Malcolm Young was my friend and the heart and soul of AC/DC.
"He will be missed and my deepest condolences to his family, bandmates and friends."
Meanwhile Canadian singer-songwriter Bryan Adams said Young's "guitar playing was a huge inspiration," adding "thanks for that."
- 'Enormous legacy' -
Malcolm Young had been suffering from dementia for the several years, and was replaced in the band by his nephew Stevie Young.
His family said he died peacefully, with them at his bedside.
His brother Angus paid tribute, saying: "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."
Elder brother George, who the band described as a mentor, died last month.
The three brothers were born in Scotland and emigrated to Australia as children with their family, although their eldest brother remained in the UK.
A statement from his family, published on the band's Facebook page, said: "It is with deepest sorrow that we inform you of the death of Malcolm Young, beloved husband, father, grandfather and brother.
"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."
Malcolm is survived by his wife O'Linda, children Cara and Ross, son-in-law Josh, three grandchildren, sister Margaret and brother Angus.