Brothers Angus Young, left, and Malcolm Young of AC/DC in 2000. (Junquer/Epa-Efe/Rex/Shutterstock)

Malcolm Young, a guitarist whose crashing chords provided the power source for AC/DC, a family band that practically came to define rafter-shaking hard rock, died Nov. 18. He was 64.

His death, of complications from dementia, was announced on the band's website. The the location was not disclosed. Mr. Young retired from the band in 2014.

Often proclaimed as one of rock's greatest rhythm guitarists, Mr. Young founded AC/DC with his younger brother, Angus, in Australia in 1973. They soon built a loyal following with their stripped-down sound of thundering guitars and drums, a throbbing bass line and screaming lyrics about hard living, lust and the spirit of rock-and-roll.

That formula made AC/DC one of the world's most popular bands, with sold-out tours and a steady stream of albums that had the sound of a headbanging artillery barrage.

"Malcolm was always saying that whatever we played has got to be tough," Angus Young told the Chicago Tribune in 1996.

AC/DC reportedly sold more than 200 million albums, with 1980's "Back in Black" accounting for almost a quarter of that total. Other hit albums included "T.N.T" (1975), "Dirty Deeds Done Dirt Cheap" (1976), "Highway To Hell" (1979), "For Those About to Rock We Salute You" (1981) and "Stiff Upper Lip" (2000). The group was inducted into the Rock & Roll Hall of Fame in 2003.

The band's basic sound was built on the twin guitars of the Young brothers, who were 20 and 18 when they formed AC/DC. (Despite rumors that AC/DC stood for "anti-Christ/Devil's Children" or for bisexuality, the band's name came from the electrical label on their sister's sewing machine.)

Malcolm Young started out playing lead guitar, but he soon yielded the spotlight to Angus, whose schoolboy uniform — knickers, coat, tie and cap — became his signature stage costume. While Angus hopped across the stage in a
Chuck Berry
-inspired duckwalk, playing heady guitar solos, Malcolm Young stayed in the background, churning out the driving rhythms and chords that formed the framework of such infectious hits as "Hells Bells," "You Shook Me All Night Long," "Let There Be Rock" and "Thunderstruck."

"Guitar aficionados will vouch for Angus' older brother, Malcolm Young, as the less-showy guitarist who is the band's most essential musician with his unerring feel for rhythm and riff," Chicago Tribune critic Greg Kot wrote in 2015.

The Young brothers wrote most of the band's songs, with help from singers Bon Scott (who died of alcohol poisoning in 1980) and Brian Johnson, who joined soon afterward.

"They're basically two quiet fellows who have taken boogie-woogie, the blues of B.B. King and Muddy Waters, and electrified it," Johnson said of the Young brothers in a 1991 interview with the Tribune. "It's great, timeless stuff. The kids may not know it's coming from B.B. and Muddy, but they're tapping their feet to it just the same."

The straightforward lyrics of tunes such as "Highway to Hell" had a defiant, roof-raising quality that appealed to the youthful, largely male listeners who were AC/DC's most devoted audience:

I'm on the highway to hell

No stop signs, speed limit

Nobody's gonna slow me down

Like a wheel, gonna spin it

Nobody's gonna mess me round

For years, critics dismissed AC/DC as an unpolished and crude, and the band won just one Grammy Award, in 2009, long after its heyday. But fans — and the band members themselves — didn't care.

"We've got the basic thing kids want," Angus Young told author Jesse Fink for his 2013 book "The Youngs: The Brothers Who Built AC/DC." "They want to rock and that's it. They want to be part of the band as a mass. . . . If you can get the mass to react as a whole, then that's the ideal thing. That's what a lot of bands lack, and why the critics are wrong."

Malcolm Mitchell Young was born Jan. 6, 1953, in Glasgow, Scotland, one of eight children. The family moved to Sydney in 1963. His father was a gas fitter.

Several family members became musicians, including Malcolm and Angus's older brother George, who was a member of the Easybeats, which had a hit in 1966 with "Friday on My Mind." George Young, who died in October, produced many of AC/DC's albums.

Malcolm Young left school at 15 and held factory jobs while trying to launch a musical career.

"I've never felt like a pop star — this is a 9-to-5 sort of gig," he told Rolling Stone in 2008. "It comes from working in the factories, that world. You don't forget it."

Mr. Young took a leave of absence from AC/DC in 1988 to overcome an alcohol problem. According to other bandmates, he never drank again.

By 2008, Angus Young began to notice his brother had difficulty remembering songs he had played for 30 years. Malcolm Young last performed in public in 2010.

He had homes in London and Sydney and is survived by a wife and two children. A complete list of survivors was not available.

AC/DC's electrifying live shows often ended with "For Those About to Rock (We Salute You)," the band's anthem to rock-and-roll:

We'll give you everything you need

Hail hail to the good times

'Cause rock has got the right of way

We ain't no legend, ain't no cause

We're just livin' for today.