A few years back, Billboard named the Neptunes -- Pharrell Williams and Chad Hugo -- the second greatest producers of the century, trailing only Swedish hit machine Max Martin.

Now Williams and Hugo are fighting it out in court.

Hugo's legal team has called Pharrell out for "fraudulently" trying to take sole control of the "Neptune" name.

Throughout their over thirty year history, [Hugo] and Williams agreed to, and in fact, have divided all assets. By ignoring and excluding [Hugo] from the any and all applications filed by applicant for the mark ‘The Neptunes,’ applicant has committed fraud in securing the trademarks and acted in bad faith," Attorney Kenneth D. Freundlich wrote in a filing.

Pharrell's team says this is all a misunderstanding.  They say they are simply trying to protect the name from third parties, and they have repeatedly tried to contact Hugo so he could get in on the filing.

"We have reached out on multiple occasions to share in the ownership and administration of the trademark and will continue to make that offer. The goal here was to make sure a third party doesn’t get a hold of the trademark and to guarantee Chad and Pharrell share in ownership and administration," they stated.

Hugo's lawyer disputes this and claims Pharrell is trying to exclude his partner of 30 years from the process.