AC/DC and the Gospel of Rock & Roll

• Video: Go Behind the Scenes at AC/DC's Rolling Stone Cover Shoot

• Photo Gallery: AC/DC Through the Years

• Photo Gallery: Behind the Scenes at AC/DC's Rolling Stone Cover Shoot

• Video: Watch behind-the-scenes footage of AC/DC at the video shoot for "Rock N Roll Train"

• The Essential AC/DC Album Guide

AC/DC singer Brian Johnson perches on the edge of a sofa in a New York hotel room with a blank look on his face, mumbling to himself in a grainy whisper, his head and shoulders drooping with exhaustion. There is nothing wrong with him. Johnson, a robust man who is built like a bear and who talks in a booming growl, is doing his imitation of AC/DC guitarist Angus Young on tour, backstage just before showtime.

"It's amazing, watching him in the dressing room," Johnson says with a raspy cackle through his thick northern-England accent. "He can be totally knackered, in the middle of a long stretch of shows, sitting there with a cigarette and a cup of tea." Johnson goes into that gnomish slouch. "Then it's, 'Twenty minutes, boys.' He gets up, hardly a word, disappears around a corner — and comes back in those clothes. He's got a fag in his mouth, a jaunty look on his face, his guitar slung on him.

"He's like Clark fucking Kent!" Johnson exclaims. "He goes into a phone booth and comes out as the 14-year-old imp, ready to rock!"

It is one of the most astonishing transformations in live rock & roll, the hilarious opposite of classic guitar heroism. At every AC/DC gig for nearly 35 years, Angus, who is five-feet-two in his stocking feet, has come out of the dressing room looking like he's headed for the principal's office, in a pre-puberty student's uniform — white shirt, tie and matching jacket, cap and shorts — based on the suits he wore to school as a boy in Sydney, Australia. Then, as drummer Phil Rudd, bassist Cliff Williams and rhythm guitarist Malcolm Young, Angus' older brother, hit the first iron riffs and sledgehammer chords, Angus erupts in a nonstop lead-guitar tantrum that doesn't quit until the final encore. He fires terse riffs and gnashed-note solos as he duckwalks furiously across the stage, bobs his head like a supercaffeinated chicken and spins on his back, his legs kicking the air. The only pause in the delirium comes during the song "Bad Boy Boogie," from AC/DC's 1977 album Let There Be Rock — when Angus drops his shorts and moons the audience.

That act and the music that goes with it — more than a dozen studio albums of strict blues-riff grammar, lewd vocal snarl and bull-elephant charge — have made AC/DC one of the biggest bands in the world. Their 1980 album, Back in Black, has sold 22 million copies in the U.S. alone. Over the past two years, AC/DC are second only to the Beatles in U.S. catalog sales, and they've sold a combined 23 million albums and DVDs worldwide since 2003, when the band moved from its longtime label, Atlantic, to Sony Music. And AC/DC's new Columbia album, Black Ice, their first studio release in eight years, is poised to be the bestselling rock album of 2008. Advance shipments by Wal-Mart, the album's exclusive retail outlet, to its stores reportedly totaled 2.5 million copies.

But there is another Angus inside that phenomenon — a passionate, quietly dogged craftsman pursuing the endless possibilities in Fifties-R&B and Sixties- British-rock guitar, in the fundamental slash and drive of Chuck Berry, John Lee Hooker, the early Rolling Stones and the Yardbirds. Offstage, without the suit, in AC/DC practice and recording sessions, Angus is "dead still," Johnson says with hushed awe. "He smiles, smokes, concentrates."

And he plays guitar sitting down.