Never Gone - and evidently, not forgotten.

Their critics have complained and their detractors predicted their doom, but in the only report that actually matters, the reunited Backstreet Boys have silenced all their opponents.

The report we're talking about is, of course, Billboard's.

In its debut week, the Backstreet Boys' comeback album, Never Gone, sold 1.5 million copies internationally and premiered at third place in Billboard's Top Ten Albums chart.

Not bad for the 1992-formed boy band which released its last album, Black And Blue, a musical-eternity ago in 2000. Still, those who have been watching the signs would have seen this success coming.

When the five, who split up in 2001, announced their reunion in March, Reuters reported that fans immediately began queueing outside their idols' homes.

In the same month, tickets available online for a series of club gigs in the US were sold out within minutes.

The hype only heightened when Incomplete, the band's first new single, was released in April. It climbed steadily up Billboard's various charts, peaked at No 10 on the Hot 100 list and headlined the digital downloads honour roll.

Even now, it's at No 25, having survived three months on the list.

With all these warnings, it's hardly surprising that the group's comeback has been proportionately explosive.

For Perfect 10 DJ Daniel Ong, 29, the band's resurgence in Singapore, at least, was a matter of course.

"Since we announced (their) reunion, their fans have been e-mailing us every single day to ask for news on them," he told The New Paper recently.

And it is this fanatical loyalty that has helped the Backstreet Boys stage such a second coming both here and worldwide, fellow DJ Jamie Yeo thinks.

In Singapore, Never Gone sold more than 6,000 copies in its first week. Incomplete stayed on Perfect 10's Top 20 list for seven weeks, peaking at No 2, and is still the reigning No 1 on Power 98's Red Hot 30, after eight weeks on the chart.

Jamie, 27, said: "The band does have new fans this time round, probably people who were too young back when the boys were first popular. But most of the album-buyers are the fans from back then."

Ms Margaret Lim, assistant programme manager of Power 98, also pointed out that these fans' continued devotion is only to be expected.

Ms Lim, 33, said: "I was a big Backstreet Boys fan myself too in those days, and I can tell you that to fans like us, Backstreet wasn't just a boy band. It was the boy band."

The new sound of the comeback album has also undoubtedly helped the band hang on to its fan base, Ms Lim said.

She added: "I'd say that they have evolved. When Incomplete came out, it was obvious. There was an older, more mature sound, which was important because it showed their maturity."

While Daniel doesn't agree that the band's direction has deviated significantly from sappy love songs, he conceded: "Their lyrics and sound have more depth now. They're more real, probably because they can actually draw on more life experiences now."

Another change is the attempt by the Backstreet Boys to dabble in currently favoured genres. In their review of Never Gone, trade magazine Rolling Stones notes that Coldplay's indie and Five For Fighting's pop-rock sounds are detectable influences.

The musical landscape now could also be a factor behind the Backstreet Boys' triumphant return.

Said Jamie: "There hasn't been a big boy band for forever, so the Backstreet Boy's decision to come back makes sense, actually, if you think about it."

This might also explain why a barrage of other similar bands have also hinted at reunions.

Mel B, former member of the once-phenomenal Spice Girls, told UK television show GMTV in May that the group is likely to launch an attack on the music scene again next year, beginning with a Wembley Stadium concert in London.

Lance Bass, of the 1990s' other boy band du jour N'Sync, also told MTV News last month that the band 'will definitely do some more music'.

But while the Backstreet Boys' sales figures will surely bolster these other reunion plans, can all of them achieve the same remarkable return?

Mr Alan Tang, label executive of Universal Music's international marketing division, thinks it is possible - with one condition.

"They have to change, as the Backstreet Boys have," Mr Tang said.

He cited the Backstreet Boys' maturity, which wins back their now-older fans, as not just a clever image move but a necessary one.

He stressed: "If these other bands want to survive, they have to evolve.

"Music is cyclical - even before Backstreet and N'Sync then, there was New Kids On The Block - so a comeback for a band is always possible.

"As long as they ensure their music stays relevant to their original fans - and this means considering these fans will now be older and more mature - I see no reason why they can't attain reasonable success."

So regardless of whether you're a flag-waving boy band-chaser, a pop CD-breaking musical purist, or a closet fan who embraces pan-genre albums, be prepared, because the scene of sounds might very well be retuned once again.