Def Leppard have never been known for being particularly avant garde, but singer Joe Elliott hinted at some potentially surprising stuff on the band's new album during a recent interview.

Speaking with Metal Express Radio during a chat you can listen to below, Elliott was asked to offer fans a few hints as to what they'll be able to expect from the group's upcoming ninth studio LP, due sometime in 2015. Although he warned that lyrics remain to be written for "four or five" of the songs, he did go so far as to say the new record might not be business as usual.

"It sounds like Leppard," he said. "It sounds like what Leppard should be doing at our age as well. It's a bit more ... I don't wanna say 'mature' -- that's the worst word you could ever say. But it's certainly not a childish record."

Lest fans fear the band is getting soft in its middle age, Elliott hastened to add that the best bits of its trademark sound remain. "I mean, there's a couple of songs on there that absolutely are typical Leppard anthemic things," he continued. "But there's a lot of cool stuff which is a lot more musical, if you like, and a lot more experimental, if you want, without being jazz or anything like that."

As guitarist Vivian Campbell recently revealed, the ball is largely in Elliott's court when it comes to getting the record finished -- work he says he'll get down to after the first of the year.

Rick Allen's and Other Rockers’ Yearbook Photos

More From Ultimate Classic Rock