Based on the strength of a whistled refrain, Peter Bjorn and John became everyone's favorite band in 2007. Two years later, they've returned with a brand-new album — one that features absolutely zero whistling.

"We had to ban it from the new album," PB&J's Peter Móren told MTV News. "We did use it on the last album. We put out an instrumental record last year — Seaside Rock — and we have whistling on that, but not a lot of people noticed. But it's not on the new album. It hasn't been banned from the gigs, though. Not yet."

So if you were a fan of the group's ultra-ubiquitous "Young Folks" (you know, the one with the whistle), you're probably going to have a hard time getting into Living Thing, their new album, which hit stores last week. And, of course, that was intentional, because Peter Bjorn and John are officially over the whistle.

"There's always pressure to make something different, but that's not because of that song; that's because you want to change your sound around and do new stuff," Móren said. "But that would've happened regardless of success. We would've changed anyway."

So they drew inspiration from a couple of rather, uh, disparate sources — like Jay-Z and Metallica. It might seem odd, but all it takes is one listen to Living Thing's infectious first single, "Nothing to Worry About," to understand how it all fits together.

"We listened to Jay-Z's 'Hard Knock Life' with the 'Annie' sample, and we needed clear, bright voices going straight through little radios," Móren smiled. "So we recorded with a children's choir. Plus, you know, cheap labor."

OK, we'll buy that. But what about Metallica? How did a trio of Swedes usurp the sheer riffage of one of hard rock's heaviest? Well, rather easily. And with reggae.

"Every album is important. It's hard to see the progression from album to album; you're looking forward 10 years, when you have 10 albums or something, and you can see how everything happens gradually. And I think Seaside Rock was an important part of that," Móren said. "If we would've gone straight from Writer's Block to Living Thing, it would've sounded less interesting. Because that was just letting off steam in the studio. [It was] a bit like 'Some Kind of Monster,' the Metallica [documentary], but rather than bringing in the psychotherapist, we played around with riffs and melodies."