You may not know it, but you're already mad about the Neptunes

Britney's a fan, so is Beyoncé. Simon Price on the production outfit everyone wants a piece of...

You may not know the name. But if you've ever screamed "I hate you so much right now!" along with Kelis, told Ol' Dirty Bastard not to worry because you've got his money, or swooned along to Britney's vows of enslavement, you're already a fan of the Neptunes.

And that's how the world's hottest production team like it. "Probably the impact of what it is that we do," ponders Pharrell Williams, crashed out on a record company chaise longue after a hard night's partying, "is that we don't announce it. Our fans love to hear a record not knowing it's us, and think 'Oh man!' when they find out. But then if you tell people in advance, they have a preconceived notion of what it's gonna be. We don't want that." The word "genius" is normally applied in the singular, conjuring images of a lone visionary engaged in the pursuit of excellence. It is seldom a plural thing, a quality shared by a group of individuals whose identities are subjugated by the whole. The Neptunes, in this way and in so many others, are a case apart. With all due apologies to the rules of English grammar, "The Neptunes is a genius."

In 1981, Chad Hugo, a schoolboy from Virginia Beach, VA, was sat in front of the television watching the American Music Awards. A troupe of showroom dummies, split unnervingly into torso-less legs and legless torsos, began dancing robotically across the screen, to the shuddering rhythm of an infectious electro track. The track was Herbie Hancock's epochal "Rock-it", and it blew Chad's mind. He spent all his savings on a Casio keyboard and a beatbox, and signed up to the school Jazz class.

It was here that he met Pharrell Williams, a singer-rapper-drummer-keyboardist. The pair hit it off instantly, and began writing songs which they performed at high school talent competitions. At one such show, they were spotted by Teddy Riley, the legendary inventor of New Jack Swing and Wreckx-N-Effect/Blackstreet member, who signed them up.

Most kids, at this point, might have thought "Wow! I'm gonna be the new Bobby Brown/LL Cool J!" Hugo and Williams, however, were interested less in personal stardom and more in learning how to work a mixing desk. "Production is just another means of expression," says Williams. "It's artistic in the same way that singing or rapping is." Under the wing of Riley, a man they still regard as a mentor, the pair patiently learnt their trade.

The name Neptunes first came to the attention of the hip-hop world in 1997, when it appeared on the credits of Noreaga's "Superthug". Black pop in the 1990s, under the influences of Dr Dre, Timbaland and the RZA, had travelled as far as it could go in the direction of brutal, freeze-dried minimalism. The time was ripe for a more expansive, fluid sound, and the Neptunes had it. Word of their refreshing approach began to spread by word of mouth, and their CV picked up names like Jay-Z, Backstreet Boys, Mary J Blige, Busta Rhymes, No Doubt and Usher.

In a world of simplistic macho beats, the Neptunes, who say they're "not really held down by the gun-slinging, ball-grabbing, Mercedes Benz-driving shit," were a throwback to the gender-transcending sounds of Curtis Mayfield, PM Dawn and Prince, making a mercurial music which sounded neither masculine nor feminine. Williams is uneasy with this sort of analysis ("I don't know, I just try to make good music, if that's what you get from it..."), but on record, there's no denying it: the Neptunes sound like they're sculpting water.

Perhaps the finest example of their quicksilver craft was "I'm A Slave 4 U", the song they wrote and produced for Britney Spears, with its wondrously woozy flat-battery beats. It must have been satisfying to make a record which was at once avant-garde and utterly populist, taking sonic weirdness to the top of the charts, planet-wide. "Oh man," Pharrell smiles, "and a privilege too!" "Slave" also destroyed, once and for all, the perception of Spears as a butter-wouldn't-melt ingénue, as she pleaded "Baby, don't you wanna dance up on me?" in one ear while panting and whispering pillow-talk in the other. She had, Williams says, no misgivings about making such a saucy track. "She totally got what we were doing all the way." Since "Slave", everyone wants a piece of the Neptunes.

The forthcoming weeks will see, in quick succession, Neptunes productions by Beyoncé Knowles, Britney (again) and Beenie Man featuring Janet Jackson. The problem with producing other people's records, of course, is that if you push them too far into left-field, they bridle. "It happens a lot," Pharrell admits. "When we try to push the limits and they don't wanna come with us. It's like anything else. If you want to really do something properly, you have to do it yourself." That's why, last year, Williams and Hugo recruited an old school friend, singer Sheldon Hailey aka Shay, to form their own group, N*E*R*D.

Their debut album, the stunning In Search Of... ("It means in search of love and happiness, in search of the bitch with the big ass, in search of why my brother smokes crack – it's wide open") was so good they made it twice. The original version, only released in the UK, was sun-kissed synthesiser soul, drawing on the Neptunes' love of Earth, Wind And Fire, Stevie Wonder and Seventies soft rock like Steely Dan and E.L.O. The second, recorded with rock band Spy Mob, was harder and more guitar-heavy. Why the remake? Shay, comatose on an adjoining sofa after last night's London gig, wakes up at this point. "We were happy with the first version, but we wanted a more organic sound. The guys who bought the first album... they've got something personal, a rarity."

The album's stand-out track, and their debut single, was "Lapdance", which juxtaposed the avarice of politicians with the striptease industry. What's the parallel they're trying to make? "They both do whatever it takes to please the person who's laying the money on the table." It was, they say, written "way before" the election of George Bush.

The name N*E*R*D is both an acronym for No one Ever Really Dies ("It's both a religious and a personal thing that we all feel"), and the obvious pun on "nerd". Were they nerds at school? "Not at all. We weren't the popular guys but we weren't the nerds either. Being in a band might have made us bad students. But no one called us nerds."

N*E*R*D's new single, 'Rock Star', from the album 'In Search Of...' is released tomorrow on Virgin records