Black Ice was also a comeback, the band's first studio album since 2000's Stiff Upper Lip. Eight years is a lifetime - probably even two lifetimes - in popular music, and there were seismic changes while they were away. Solo artists rose up to overthrow the rock group, with even boy bands ceding their late '90s dominance to new pop icons such as Beyonce, Justin Timberlake, Britney and Pink. The noughties were also largely a decade for the girls, 10 years in which popular music was created - and consumed - primarily by women. But AC/DC remained somehow unaffected, bursting back into the charts as if it was 1976 all over again and they were still slowly motoring down Swanston Street on the back of a flat-bed truck singing Long Way To the Top.

So what is it about AC/DC that enables them to remain the only big, blokey rock'n'roll band left on a world-conquering level? Admittedly, the Rolling Stones are still out there doing their thing, but their thing is far more pouty and ambiguous, and it's the same with current rock pretty boys Kings of Leon. AC/DC have always been plain, and have always made plain, meat and potatoes rock'n'roll, with hard riffs and suggestive, fun-loving lyrics. And they're the only band like that still standing. Of course, AC/DC have a big story - the death of larrikin lead singer Bon Scott, who choked on his own vomit in the back of a car on a cold London night in February 1980, the victim of his own remarkable capacity for good times. And then the band's triumphant return later that year, with flat-capped new vocalist Brian Johnson and their biggest album ever, Back in Black. They also have an image - namely lead guitarist Angus Young's eternal schoolboy uniform of blazer, shorts, cap and tie. Supposedly, Young went through a variety of potential outfits, including a Superman-inspired look entitled "Super-Ang", before settling on the original uniform from his time at Ashfield Boys High School in Sydney. It's a great gimmick, giving the band a kind of perpetual innocence that belies their meaty, ribald rock'n'roll. But the real key to their survival goes beyond mere image or back story. After forming in late 1973, the vision of teenage Angus and older brother Malcolm, AC/DC settled on their format the following September, when Scott replaced original vocalist Dave Evans. Since then, AC/DC have been a constant, virtually unchanging presence in popular music, making record after pretty much interchangeable record.

It's this monolithic constancy, usually a career killer in a novelty-hungry music industry, that makes AC/DC just as popular in 2010 as they were in 1980. Lead singers aside, they haven't changed a bit, and fans return to each new record or tour like they've never been away. Ever reliable, always catchy, and never that good looking in the first place, AC/DC are ageless, changeless and therefore perennial. "Someone said to Angus the other day, 'Hey, you've made the same album 15 times'," Johnson told The Scotsman last November. "Angus said, 'No, man, we've made the same album 16 times'."

The band are such a no-fuss operation, shot through with Australian self-deprecation despite their Scottish and English roots, that it comes as a surprise to discover exactly how popular they really are. Their theatricality may be limited to concert pyrotechnics, an oversized inflatable Rosie doll, and Angus' thrashing guitar spasms, but they still deliver extraordinary figures. Not only did the band outsell the Beatles to become the No. 1 catalogue artist in the US in 2008, but Back in Black is the highest-selling album released by any band. The 1980 classic has sold about 45 million albums worldwide, pipped only by Michael Jackson's Thriller. No wonder AC/DC have stuck to a winning formula. The Young brothers may have chucked out drummers and bassists over the years, worked with maverick producer Rick Rubin on 1995 album Ballbreaker, and even released Black Ice exclusively through Walmart stores in the US, but when it comes to the crunch, they're canny enough to return to what they know best. "We've always been a rock'n'roll band," Angus said in a '70s television interview, looking to his brother Malcolm for support. "That's always what we played, and that's what we always wanna keep playing." The quiet one, Malcolm nods and mutters a gentle agreement. The Youngs' thicker-than-water bond is also central to their longevity. Just 18 and 20 when the band formed, the brothers are AC/DC's heart and soul, with lead guitarist Angus the visual focus and rhythm player Malcolm the organisational brains behind the group. Together they've written the bulk of the band's songs, at first with input from Scott, and then less so from Johnson, who hasn't written any of his own lyrics since 1988.

Not only that, but older brother George preceded his siblings into show business with the fantastic Easybeats, one of Australia's first groups to find success overseas with their 1966 single Friday on My Mind. Acting as mentor, producer and even sometime bassist in their early years, George's experience and his concern for his kid brothers has been crucial to their success. The closeness is not limited to the Young family, either. Bassist Cliff Williams has been with the band since 1977, and long-time drummer Phil Rudd returned to the fold in 1994, more than a decade after a drug-fuelled punch-up with Malcolm saw him ousted from the band. Their three most recent albums have all been recorded with this line-up, the very same that made Back in Black and its chart-topping follow-up For Those About To Rock.

"They're very loyal," says concert promoter Garry Van Egmond, who has worked with AC/DC in Australia, New Zealand and Japan on each of their tours since the early '80s, including their upcoming Black Ice dates. "You can imagine the inquiries they would have got from other promoters wanting to make an offer on the tour, but they didn't consider it; they showed their loyalty towards me." Van Egmond attributes the band's longevity to a successful bridging of the generation gap. "There's now really three generations of AC/DC fans," he says. "It's 12 or 14-year-old kids, it's their father and it's their grandfather. People up to 60 or 70 years of age are buying tickets." But kids don't listen to their parents' records, let alone their grandparents', unless there's something in the songwriting that translates across the decades. Starting with AC/DC's first single Can I Sit Next To You Girl, recorded with original vocalist Evans (Scott reprised it on their second album T.N.T.), the band has understood the power of the double hook, combining immediately infectious guitar riffs with fresh, cheeky choruses for an irresistible one-two knockout. Their last mega-hit was 1990's Thunderstruck, but every album includes a couple of tracks worthy of gracing any AC/DC best-of.

"We often have that debate among all the music industry guys," says veteran Melbourne music manager Ralph Carr. "Why have AC/DC stood the test of time? I think the main reason is the consistency of great songs. High Voltage, Highway To Hell, Back in Black, all those hits . . . They had that consistency, and that's what I think is lacking in today's world." Carr has been an AC/DC tragic since seeing them as a teenager in 1977 at Heidelberg Town Hall. "There was an all-in fight and I ran out," he recalls. "I think Bon Scott enjoyed it; he jumped into the crowd." But as manager of the likes of Kate Ceberano and Vanessa Amorosi, Carr is also well aware that the music world of 2010 is a lot less band-oriented, less rock-oriented, and even less maleoriented, than ever.

"Females tend to buy a lot of records these days, but also there's just no great male performers," Carr says. "We're seriously looking for them every day, but there hasn't been the same amount of great male performers as female. I go for any genre as long as they're talented, and I'm desperate to find a band or a male artist ... but there ain't a lot out there." Still, it's a sign of AC/DC's unending currency that they can hold their own against the current queen of urban-influenced rock, Pink. The hugely popular singer tipped her hat to AC/DC on her Funhouse tour last year, warming up Australian audiences with a rip-roaring version of Highway To Hell. Van Egmond predicts AC/DC's Black Ice tour ticket sales will outstrip Funhouse's 550,000 by a good 70,000. "There's a much larger female audience than we've had previously," he says of the Black Ice tour. "(For women) AC/DC have have crossed over from heavy metal into a mainstream band. Their appeal has widened so much." The two acts also had a close tussle on the charts. AC/DC prevented Pink from getting her first US No. 1 album when both released their latest albums in October 2008. Black Ice relegated Pink's Funhouse to a No. 2 debut, maintaining its perch at the top for two weeks, while in Australia Funhouse replaced Black Ice at No. 1 after a week, and went on to spend nine weeks there.

Female artists may reign supreme on the music charts these days but clearly AC/DC are a tough act to beat. For certain kinds of men and women, from teenagers to retirees, AC/DC represent something innate and eternally satisfying - a love of simple, uncomplicated good times. Thirty-six years into their career, there's absolutely nothing unexpected about the band. As ex-Go-Between and sterling music critic Robert Forster wrote in The Monthly, "There has always been an if-it-ain't-broke ethos in the band that reflexively rejects any criticism of the simplicity and grunt of the melodies, or the limitations of the sound." AC/DC have proved that simplicity, grunt and a few self-imposed limitations can be the key to a never-ending musical career. Strange, then, that Forster believes Angus Young should drop the schoolboy schtick, saying it's "a trap, and the older Angus gets, the sillier it looks". He's right that it's a trap, but Young sensibly resigned himself to captivity long ago.

An Angus Young in civvies would be about as interesting to AC/DC fans as Kiss without make-up was to theirs. So steadfast and reliable have AC/DC been since 1973, that were Young to ever hang up his uniform, the band would surely die a sudden death. ACCA DACCA AT THE TOP AC/DC have sold more than 200 million albums worldwide, including 71 million in the US alone.

The band got their name from initials written on their older sister Margaret's sewing machine.

Malcolm Young's first band was a Newcastle group called the Velvet Underground, who must have been blissfully unaware of Lou Reed's band of the same name.

Despite being the second-biggest selling record ever released, Back In Black only reached No. 4 on the US charts.

only reached No. 4 on the US charts. Alistair Kinnear, the last man who saw Bon Scott alive, was long assumed to be a fake name for someone who didn't want to be identified. But Kinnear emerged in 2005 to speak to the press for the first time in 25 years.

When the Young family emigrated to Sydney from Glasgow in 1963, oldest son Alex chose to stay behind, and went on to form the London-based band Grapefruit.

AC/DC were Australia's top earning band last year, with reported takings of $105 million, displacing the Wiggles from their four-year run at the top.