Pharrell Williams is happy to be just one of the band again

Name a pop music A-lister, and he or she has either worked with Pharrell Williams or probably wants to. Gwen Stefani, Jay-Z, Britney Spears, Kanye West, Snoop Dogg and Madonna all fall into the first category. Need more proof?

But as he has transformed himself into one of the three or four most important figures in popular music as half the production team the Neptunes — as well as a fashion designer, model and single-named icon — Williams has managed to keep an important part of his past with him, one which is about to resurface in a determinedly modest club tour.

The band N.E.R.D., which Williams formed several years ago with childhood friends Chad Hugo and Shae Haley, is more than just the side project for which it's often mistaken. It's more than merely the outlet for all the songs that don't fit the sleek template the Neptunes have created — a futuristic fusion of skeletal R&B and hip-hop that has launched what seems like a thousand hits, including Britney's "I'm a Slave 4 U," Nelly's "Hot in Herrre," Justin Timberlake's "Rock Your Body" and Kelis' "Milkshake."

"It's simply the way we truly express ourselves," Williams says of N.E.R.D. "I'm pretty sure Chad and Shae feel the same way."

The fact that one of music's most ridiculously busy men is taking time to do this interview (from the New York offices of his label, Star Trak) says something about his commitment to the project. But as N.E.R.D. prepares to release a third album, N.3.R.D., which the group will support with a short club jaunt before joining Kanye West's "Glow in the Dark" tour this spring, Williams sounds more than just enthusiastic. He sounds, perhaps, relieved.

"If you get the right copy of the album," Williams says, "you'll hear me say at the beginning, It's been awhile since we were able to express ourselves. That was really important."

Getting Williams to actually describe the sound of N.3.R.D., and how it compares with the mashup of R&B slink, Steely Dan smarts and alt-rock muscle of the band's first two albums, is a bit more problematic. The phrases Red Bull and a nice, refreshing drink of water come up more than once, as do the words energy and emotion.

"Well, there's no resemblance to anything we've done before. There's fingerprints of it," he begins. "But you can't compare it to anything else, and I'm not just saying that to sound hip. Energy and emotion were the two most important words in the making of this album. And if a track doesn't get you both, it's definitely one or the other.

"It's unfair to compare it to other stuff," Williams adds, "because most other records aren't made that way."

Williams reports that all of the album's tracks have been recorded, but a handful remain to be mixed. For now, the only reference point is the single "Everyone Nose." The song's jazzy, skittering hip-hop isn't far from the spare and playful Neptunes sound that Williams created with Hugo, which has dominated the charts for most of the past decade.

In the song, the narrator is about to explain what's keeping All the girls standing in the line for the bathroom locked out ("It's an observation," Williams says wryly. "Everybody knows what's going on in there"), but he's interrupted by a sudden swell of romantic R&B.

The midsong switch is just one example of Williams' ongoing effort to avoid falling into a rut. He explains that on N.E.R.D.'s second album, 2004's Fly or Die — on which he and Hugo learned to play their own instruments — the group's sound had become too consistent. "We just wanted to start changing things up again," he says of the new album.

That's not the only thing that's changed in the past four years for Williams and crew. Following the release of Fly or Die, Williams announced that N.E.R.D. had broken up, citing issues with the group's label at the time, Virgin, only to recant a week later. He next embarked on a solo career that received mixed reviews from critics and seemed to be something that Williams was never comfortable doing in the first place, as his sometimes tortured-sounding interviews from the time strongly suggested.

Even today, talking about the release of the 2006 solo debut, In My Mind, and its short, subsequent tour, Williams sounds apologetic.

"I hadn't thought it out fully," he says with a sigh. "I just hadn't realized until I got onstage how it was so ... [pause] funny, doing an R&B song and then a hip-hop song. It's one thing on other people's records, but ...," he says, then trails off.