Four years ago, when Justin Timberlake was looking for material for his first solo album, he turned his ill-fated romance with childhood sweetheart Britney Spears into the hit single "Cry Me a River."

But now, as he prepares his second album, the 25-year-old pop prince says he’s turning to the early recordings of David Bowie and David Byrne to find a new sound.

The former boy band heartthrob now faces the difficult task of producing a follow-up to "Justified," an album that sold 7 million copies and guaranteed a pop career beyond *NSYNC reunions.

Timberlake’s fans will be in for a surprise. His first single, "SexyBack" - from on his next album, "FutureSex/LoveSounds," which will hit the charts in September - won’t feature his trademark falsetto.

"The best way I can describe that song is say David Bowie and David Byrne decided to do a cover of James Brown’s ’Sex Machine’," Timberlake said at a press conference Friday in Paris, as he began a string of shows in Europe.

In Synch with Something New

Timberlake said Bowie and Prince were especially big influences on his latest work, in which he hopes will build his credibility as a recording artist. He said he’s also been listening to soul legends Al Green and Marvin Gaye, as well as The Beatles and The Eagles.

"I think it’s important on your sophomore album to broaden your sound, to try something new," Timberlake said. "Because if you do the same thing, then your third album has to be the same thing, and your fourth album has to be the same thing and you don’t grow."

"I realize that I have a platform to push the sound of pop music," Timberlake continued. "That’s the only responsibility that I put on myself in recording the album."

Not sure how fans would react to the new sound, Timberlake said he put a rough cut of "SexyBack" in his car and sprang it on friends unannounced to see how they’d react.

"I think the proof was in the head nod," he said.

No Questions About Cameron, Please

Timberlake’s press representatives asked reporters not to question the singer about his girlfriend Cameron Diaz, who has reportedly joined him on his latest tour.

While the singer has been slow to release his second album, he’s also been focusing on his acting. In the months to come, he’ll appear in "Alpha Dog," directed by Nick Cassevetes, "Black Snake Moan" with Christina Ricci and Richard Kelly’s "Southland Tales," which competed for the prestigious Palme d’Or award at the Cannes film festival.

Though looking to shift his career into the next stage, Timberlake is nevertheless falling back on many of the artists who helped make "Justified" a monstrous success, including rapper/producer Timbaland, as well as will.i.am of the Black Eyed Peas and T.I.

"I knew I wanted to work with Timbaland again," he said. "" I remember calling him on the phone and asking him if he thought we could do five or six ’Cry Me A Rivers.’ It is a lofty challenge, but Timbaland is the type of producer that when you call him and say that it challenges him, he doesn’t back down from that, and that is something that I knew I would get from him."