The closing arguments in Robin Thicke and Pharrell Williams' Blurred Lines copyright infringement trial are expected to be presented in court on Thursday afternoon (05Mar15), two weeks after proceedings began.

The two hitmakers are fighting soul legend Marvin Gaye's kids over claims they borrowed heavily from his 1977 classic Got to Give It Up while creating their 2013 hit.

Both Thicke and Williams have testified, with the former confessing he lied when he claimed to have had a bigger role in the creation of the song, and Pharrell telling the court on Wednesday (04Mar15) he was not thinking about Gaye or his music when he came up with the hit.

During the trial, Thicke performed a medley of classic tunes on a piano in an effort to prove to the jury that many great songs have similar hooks and chord progressions.

But Gaye's children maintain Blurred Lines is too similar to their father's Got to Give it Up, and they're seeking a cut of the 2013 hit's profits. Marvin Gaye's ex-wife Janis, the mother of his children, told the court she was convinced Thicke's hit had been taken from Got to Give It Up, revealing she was stunned to discover the songwriters hadn't licensed Gaye's work.

She testified, "It's the living legacy Marvin left behind for his children, his family, his fans and the world."