WEST HOLLYWOOD, California -- Good Charlotte are used to churning out radio-friendly punk-pop, but for their upcoming fourth album, the guys are looking to the past for inspiration.

"Right now, I'm really into '80s music like Cyndi Lauper and Tiffany, and I think that's kind of the vibe that came across a little bit with [Hilary Duff's] new stuff," Benji Madden told MTV News at a Blender magazine-sponsored party for X Games 11 at the Key Club, where he played DJ for a portion of the evening.

Good Charlotte fans can expect a bit of that retro beat on their next LP, which they plan to begin recording in December. "We touched on it a bit on our last album [The Chronicles of Life and Death], and there will definitely be a few songs on the new record that will go in that direction," Benji said.

Benji and twin Joel head up their own writing-and-production team, dubbed the Dead Executives, and produced all three new tracks for Duff's forthcoming best-of LP Most Wanted, out August 16 (see [article id="1503561"]"Cheaper By The Duo? Hilary Duff Teams Up With Madden Brothers For New LP"[/article].)

"I recorded mainly with Benji and he's crazy, so it was fun," Duff said last month at launch of her Still Most Wanted Tour. But Madden notes he actually held himself back from getting too wild in the studio with his brother's recently outed main squeeze (see [article id="1506032"]"Hilary Duff, Joel Madden Go Public With Lovestyle Of The Rich And Famous"[/article].)

"[Hilary's] like my little sister now and we have a lot of fun with her, but I was actually pretty mild with her when we were in the studio," he laughed. "I've been a lot worse, so with the girls, you know you have to be gentle."

All joking aside, Madden says he is very proud of the material he and the maturing pop princess churned out. "I love the work we did with Hilary," he said.

The Madden brothers have been busy penning tracks not only for Good Charlotte, but for other musicians as well. "We always have songwriting sessions with people, so we'll see what actually makes it out there. You never know until it happens, but I'd say we'll have a couple other things coming out later this year."

The two would like to broaden their musical horizons and have even drafted an eclectic wish list of artists they would like to work with, including Justin Timberlake, Christina Aguilera, Nine Inch Nails and Marilyn Manson.

"The phone has definitely been ringing off the hook," Madden said. But for now, the guitarist said his primary focus will be on the re-emergence of Good Charlotte.

"Joel and I are kind of holding off right now because we really want to concentrate on the band, but when we get that all wrapped up, we'll definitely focus on other things."