The Neptunes produced Britney Spears 'Slave 4 U'
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23 Amazing Facts You Didn't Know About Pharrell Williams

10. The Neptunes produced Britney Spears 'Slave 4 U'
It was the producing duo's first number one single when it topped the charts in 2001- an achievement that would get them noticed in the industry and lead to many more hook-ups.