Robin Thicke and Pharrell Williams have won a minor victory in their ongoing legal spat with Marvin Gaye's kids - the siblings won't be allowed to play their father's music in court.

Gaye's children sued the hitmakers in 2013, claiming their song Blurred Lines was a rip-off of the late soul man's 1977 tune Got to Give It Up.

As next month's (Feb15) copyright trial looms, a federal judge has ruled he won't permit Gaye's recording to be played during the trial. As a result, the Gaye kids will have to book a live musician to perform the song on their behalf.

U.S. District Judge John Kronstadt told Gaye’s heirs they can only pursue their copyright claim if they agree to use a musician, who will play their father's written composition on a keyboard, because they don't own the performance or recording rights to the song.

The siblings' lawyer Richard Busch tells the New York Daily News, "We obviously disagree with the decision, and we are exploring our options."

Thicke and Williams' legal representative Howard E. King says, "We’re gratified that the judge recognised they can’t play the sound recording, which has all kinds of elements that are not in the written composition.

"I love Marvin Gaye. My clients love Marvin Gaye. But this is not about his voice, his character, his charisma. The question is whether Blurred Lines is a copy of what he wrote in the sheet music. And it's not."

The copyright trial is scheduled to begin on 10 February (15) in Los Angeles.