Brian Johnson has paid tribute to his AC/DC bandmate Malcolm Young, calling him a "genius" whose "riffs have become legend, as has he."
Malcolm died on Saturday at the age of 64. He had been suffering from dementia for at least the past three years.
In a post on his official web site under the title "For 32 Years We Stood Side By Side On Stage," Brian wrote: "I am saddened by the passing of my friend Malcolm Young. I can't believe he's gone. We had such great times on the road.
"I was always aware that he was a genius on guitar; his riffs have become legend, as has he.
"I send out my love and sympathy to his wife Linda, his children Kara and Ross, and Angus, who will all be devastated, as we all are. He has left a legacy that I don't think many can match.
"He never liked the celebrity side of fame; he was too humble for that. He was the man who created AC/DC because he said there was no rock and roll out there.
"I am proud to have known him and call him a friend, and I'm going to miss him so much. I salute you, Malcolm Young."
Malcolm retired from AC/DC, the group he formed in 1973 with Angus, in 2014 after it was made public that he was suffering from dementia.
Angus carried on as the sole original member of AC/DC, with his and Malcolm's nephew Stevie replacing Malcolm in the lineup for the recent "Rock Or Bust" LP and tour.
Malcolm's exit ended up being the first in a string of departures that included longtime drummer Phil Rudd, who was confined to house arrest after being found guilty of drug charges, and Johnson, who faced total hearing loss if he stayed on the road. Bassist Cliff Williams also announced his retirement after a nearly 40-year run with the band at the end of the "Rock Or Bust" tour.
Angus did assemble a new lineup to complete the band's touring commitments last year, including GUNS N' ROSES frontman Axl Rose on the mic, but has not made any public announcements yet about the group's future.