Came across this great article on N.E.R.D. in Remix, where the secret to Pharrell's drumming is revealed.

By now, it's clear the secret weapon behind many of N.E.R.D's tracks (as well as Neptunes' productions, including Gwen Stefani's “Hollaback Girl”) is Williams' generous use of bucket drumming to enhance programmed rhythms. From Los Angeles' Record Plant and Miami's South Beach Studios to N.E.R.D's Hovercraft Studios, Williams maintains a sizable bucket collection to match every sound in his arsenal of rhythmic drum wizardry.

“Every studio we go to Pharrell asks, ‘Do you have my buckets set up?’” Coleman says with a laugh. “He uses anything: a paint can, a big 50-gallon drum, trash buckets. Pharrell typically plays 20 buckets at once. He'll use one like a deep trash bucket for the kick sound, then one with a sharper attack for a snare sound, metal buckets for a percussive feel. He will go from bucket to bucket. It's not like he's playing all the buckets as a kit. He will program a kick and a snare, then we will go behind that and use different bucket sounds to add to the programmed sounds. We put buckets on everything, even recent tracks with Missy Elliott. Sometimes we just empty the garbage from the bathroom trash cans and use those in the studio. It's almost a secret, but it's just buckets, man. It's really hype, and it's really raw. It is what gives their music that crazy raw feel and a lot of attack.

Not a bad trick, I confess I've used some similar techniques, though nothing as drastic as that. Haven't heard the new N.E.R.D. album just yet, but I'm sure if you listen closely you'll be able to hear what's being described.

Very rarely do producers let out any real secrets (you know, like just jacking loops from Garageband and selling them to Usher), so kudos to Pharrell for letting the cat out of the bag. Now who's gonna jack his whole steez and start doing the same thing?