Many boy bands of yesteryear have seen their time and whittled away into faded memories of concert programs and t-shirts, likely hidden at the back of the closest.

Though bubble-gum pop band New Kids on the Block have been resurrected, the ever-familiar Backstreet Boys have never left the music scene. It’s hard to believe that 15 years have passed since they first stepped into the music world and broke concert sales records.

Even with all hardships such as major health issues, substance abuse and the loss of one member, Kevin Richardson — the Backstreet Boys just keep on going.

“It was a little difficult at first, but we were cool with it. (Kevin) moved on and so have we. We’re comfortable with what we do as four and it’s still just as strong,” Nick Carter tells Metro.

“Competitive spirit that’s just in every single one of us, and to be the best that we can be as a team, as a group and musically, we feel that what we stand for is honesty and purity in great music that people love,” he says.

Even though the guys — Carter, AJ McLean, Howie Dorough and Brian Littrell — have taken time to get married, start a families and even pursue solo projects they’ve still managed to work together as a group.

Their last album, Unbreakable (Jive Records), came out last October and carries a lot of what they’ve always been known for — indelible melodies, catchy hooks and finely crafted three and four part harmonies.

“I think the most challenging part was kind of figuring out who the new Backstreet Boys are … because that was an issue when Kevin had left the group,” says Carter. “I think we kind of doubted ourselves at certain times — but once we realized we were confident, I think that it turned out to be really good and we’re excited.”

With all the boy bands out there and those like the New Kids on the Block trying to make a comeback, Carter says the group isn’t worried about staying strong.

“Only time will tell, we’ve been around for 15 years and we really haven’t left the scene,” he says. “We are rooting for the New Kids on the Block to succeed. We want them to be successful because we feel that sort of music and what we represent is what this world needs again.”

As for what’s next, the guys plan on hitting the studio following the current tour so look for another album in the next year.