From Mystikal's ''Shake Ya Ass'' to Britney Spears' ''I'm a Slave 4 U'' and Justin Timberlake's ''Rock Your Body,'' the Neptunes pump out more hits than Mike Tyson on a bender. By slipping '70s funk and soul into hip-hop (Snoop Dogg's ''Beautiful''), making pop out of minimalistic R&B (Timberlake's ''Justified''), and recording the groundbreaking rap-rock album ''In Search Of...'' (in their guise as the band N.E.R.D.), the production duo has shattered walls between musical genres. With their album of all-star collaborations, ''The Neptunes Present... Clones'' (which includes Jay-Z, Busta Rhymes, and the Clipse), due in stores Aug. 5, Chad Hugo and Pharrell Williams tell EW.com about working with Timberlake, writing their songs, and what they have planned for their second N.E.R.D. album.
The words ''featuring Pharrell'' pop up on a lot of hit songs. How many of those do you think you've done?
WILLIAMS I really wasn't paying any mind to it, but I'm not really gonna do too many of those records [in the future]. I don't want to O.D.
What do you mean?
WILLIAMS I've never really been the kind of person to stick with the same thing. I wore trucker hats for a very long time, and I don't wear those anymore, as much as I love to see my fans in them. I used to do the Neptunes sound, like, [sings] ''Woo, woo, woo,'' but the last six or seven months I'll be, like, ''Ho!'' instead. Things are seasonal -- it's like a fashion line.
What's your writing process like?
HUGO For a typical song, Pharrell will come up with a beat, and he'll have the hook in his head, including bass lines and keys. And he'll have vocals done. I'll come in and maybe beef it up. I'm like the band in that case -- I'll just come in and fill in the blanks, sometimes take stuff out and replace things. That's how about 60 percent of the stuff is done. Other times it's me and him vibing, working on chords together. But essentially Pharrell's a drummer and I'm a keyboard guy. I play guitars and bass a little more, too.
And where are you with a second N.E.R.D album?
WILLIAMS It's called ''Fly or Die,'' and I love it to death. It's halfway done; we'll put it down in November. It's rock [again], and we're doing it ourselves. Originally, we played the other one ourselves and then let Spymob go in and play the instruments live. But this time we're just starting it out live all the way ourselves. We've been playing live on a lot of the production we've been doing for other people. Like the Justin Timberlake sh--, that's all live.
HUGO I'm not gonna play no Eddie Van Halen licks on the guitar. It's just about making songs and wanting people to sing along with us. I'm basically a barre chord guy, but most punk bands are too. We'll stack other instruments on top and fill in the blanks that way. The new album is gonna sound like us, but there's a lot of influences from the '60s. It's got that swing sh--, a couple of swingy, Beatle-esque-type songs. It's also got Pharrell singing about some political issues, like, ''I don't wanna go to war.'' We're not trying to preach at anybody, though.
''Rock Your Body'' is in the top 20. How would you compare Justin Timberlake to other artists you've produced?
HUGO He's self-contained. He wrote his own harmonies, his own riffs. The only difference is he's white, but he's dope. The kid's got soul.
And how about Britney?
HUGO She works hard. She created herself as an icon -- like the girl next door, but successful.
Who's the role model for the career you want to have?
HUGO If I didn't see Stevie Wonder on ''The Cosby Show'' a long time ago with a sampler -- sampling ''J-j-jam it on the one,'' I don't know what I'd be doing. There's lots of sh-- I wanna do, so I just bounce around. I try to do different things. There's lots of different people [who are role models]. But I would say John Lennon -- a mix of him and Afrika Bambataa.