His previous absence was never as glaring as, say, the receding hairlines onstage Tuesday night, but newly returned Backstreet Boy Kevin Richardson did manage to put his rebounded group’s Xcel Energy Center concert into better perspective.

“We have babies now, and I know many of you have babies, too,” said Richardson, back after quitting the group in 2006.

Richardson’s hiatus mirrors a lot of fans’ ambivalence for the late-’90s teen-throb pop quintet over the past decade. But for reasons maybe having to do with adult escapism or a One Direction-spurred nostalgia for boy bands, Backstreet really is back.

The five original members were greeted with nearly the kind of pandemonium they generated a decade and a half ago. Tuesday’s show drew about 12,000 fans, most of whom have to get up and go to work (not school) in the morning and explain why they lost their voices. Good luck if that responsibility happens to be taking care of a 3-year-old.

While the quintet updated its repertoire to include such newer songs as “Show ’Em (What You’re Made Of)” — the ode to fatherhood introduced by Richardson — the bigger treat for Tuesday’s crowd seemed to be the old, dated but still irrepressibly youthful material. Or, as Richardson put it to a rousing reception: “Are we gonna party like it’s 1999?”

Oh, they partied all right. There’s nothing like letting your inner-15-year-old come out with help from adult beverages. Any signs of inhibition over singing silly, teenybopper love songs were lost by the second number, “Don’t Want You Back.” For that one and the show opener, “The Call,” the boys danced and harmonized in sync in ways that might even make their old ’N Sync rival Justin Timberlake want to be in a crew again.

In the end, Backstreet Boys have gone down as the biggest-selling group of the modern boy-band era — take that, JT! — and they made a point of reminding Tuesday’s crowd just how many hits they racked up. The tender gushers “Show Me the Meaning of Being Lonely” and “I’ll Never Break Your Heart” came early in the evening, and “Everybody (Backstreet’s Back)” and “Larger Than Life” were saved for the encore finale. For the latter, the guys donned larger-than-boy-band-sized Minnesota Wild jerseys that briefly made them look pipsqueaky 18 again.

Now ranging in age from 34 (Nick Carter, still the hearthrobbiest Boy) to 42 (Richardson), the boys can still carry the sex-symbol heat — even when they’re doing so tongue-in-cheek, such as when Howie Dorough demonstrated how to “shake what his mama gave him” during an unplugged segment mid-concert. Yes, even the Backstreet Boys are now playing the MTV Unplugged card, donning acoustic guitars for more hits, including “Quit Playing Games With My Heart.”

“Your favorite boy band is actually playing instruments,” Carter quipped. Never mind that the box Richardson pounded on for rhythm was debatable as an “instrument.”

Of course, the instruments that really mattered were the voices, and there was no debating their value. Even during their cheesiest, most outdated, fly-boy-wannabe moments — “We’ve Got It Goin’ On” could have been mistaken for a Color Me Badd hit — the fellas harmonized together as impressively as any male vocal group this side of Il Divo. Let the older ladies have those opera hunks, though. Tuesday’s crowd proved it’s still young enough to enjoy the pop studs.

Canadian pop/rocker Avril Lavigne opened the show with a short and very, very sweet set. The former teen bubble-gum punk, now 29, wore a skeleton-with-garters ensemble she never could have donned at 17, when she first hit the charts. However, she mostly stuck to singing the chirpy songs from back then, including “Sk8ter Boi,” in which she aerobically jumped around the stage runway like Olivia Newton-John getting physical.

The crowd — unusually full for an opening act — sang along and waved cellphone lights Bic-lighter-style to the syrupy power ballad “I’m With You.” Lavigne avoided her controversial recent single “Hello Kitty” and any other hint of a new edge, making her final song, “Complicated,” sound extra fitting. Nothing complicated here.


See Backstreet Boys’ set list and photo gallery.