Oh, it's ON!

Robin Thicke, T.I. & Pharrell have filed a preemptive lawsuit against the estate of Marvin Gaye after the late singer's family and record label made claims that "Blurred Lines" steals from Gaye's song "Got To Give It Up."

The suit alleges that the trio of singers is being wrongly accused and that "being reminiscent of a sound is not copyright infringement." Thicke adds "the intent of producing 'Blurred Lines' was to evoke an era" not a specific song.

You be the judge...