The rumors that Stic.Man and Jay Electronica wrote portions of Nas album Untitled blew the lid off of the industry's not-so-hidden ghostwriting secret, but the same has yet to happen on the production side. And rest assured, it happens there too. And we're not even talking about the obvious beat-jacks, like the Trackmasters ripping a Beatnuts track for Jennifer Lopez.
A few rumors, some unconfirmed: Minnesota may have produced "All About the Benjamins." DJ Quik did the drums on "In Da Club." Large Professor may have done the drums on "T.R.O.Y." Danja was heavily involved in producing some of Timbaland's latter-day work.
Industry stories about stolen samples and beats are rampant; collaborative work and production credits don't always align. The work of individual producers are credited to "The Hitmen." The music world is a shady place, and beatmakers, with little financial incentive in the industry, can be the most vulnerable.