Just came across this article in The Hollywood  Reporter:

Robin Thicke Sues to Protect ‘Blurred Lines’ from Marvin Gaye’s Family

Here’s a link to a PDF of the lawsuit

In short:

Plaintiffs, who have the utmost respect for and admiration of Marvin Gaye, Funkadelic and their musical legacies, reluctantly file this action in the face of multiple adverse claims from alleged successors in interest to those artists. Defendants continue to insist that plaintiffs’ massively successful composition, ‘Blurred Lines,’ copies ‘their’ compositions.”

The suit claims the Gaye family is alleging that “Blurred Lines” and Gaye’s “Got to Give It Up” “feel” or “sound” the same, and that the “Gaye defendants are claiming ownership of an entire genre, as opposed to a specific work.”

Have a listen:

Marvin Gaye – “Got to Give it Up” (1977)

Robin Thicke – “Blurred Lines” (2013)