Watch: One Direction Dishes on New Album ‘Four’ Backstage at iHeartRadio Fest

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Niall Horan, Harry Styles, Liam Payne, Zayne Malik, and Louis Tomlinson of music group One Direction pose in the press room at the iHeartRadio Music Festival Night 2 at the MGM Grand Resort and Casino on September 20, 2014 in Las Vegas, Nevada. 

1D members dish on what fans should expect from the group's new album.

Classic, natural, simple, crazy and upbeat. These are just a handful of words that One Direction’s Zayn Malik and Louis Tomlinson use to describe the pop group’s forthcoming album, Four.

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“There’s a good balance,” Tomlinson tells Billboard backstage at the 2014 iHeartRadio Music Festival in Las Vegas. “It’s definitely our most different sounding album. We’ve definitely tried to keep it different, really.”

1D recently announced that its next single “Steal My Girl,” a preview of November’s Four album, will be released in late September. But the group kept things strictly to the hits during its iHeartRadio Fest performance on Saturday (Sept. 20). Check out a clip of the performance below.

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Backstage, however, Malik and Tomlinson dished on what fans should expect from 1D’s new album.

“I think it’s just a progression on the last stuff we’ve done,” Malik explains. “We haven’t tried to go too different with it. We tried to keep what is our sound, but just kind of grow with it as we’ve obviously grown up. We’ve grown a bit more facial hair. And our lyrics need to get a little older as well. So we just kind of want to grow with our fanbase.”

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One Direction promptly left Las Vegas to continue with it’s current world tour of stadium and arenas. The group was scheduled to play the Alamodome in San Antonio on Sunday (Sept. 21), with additional dates scheduled through April 2015.