Los Angeles (CNN) -- Robin Thicke's summertime hit "Blurred Lines" is an illegal rip-off of Marvin Gaye's "Got to Give It Up," Gaye's children claim in court documents filed Wednesday. Fans, journalists and music experts immediately recognized similarities between Gaye's 1977 hit and the 2013's summertime smash, Gaye's heirs contend. The controversy is a high-stakes legal fight involving an alleged conflict of interest with Sony-ATV, the music publisher half-owned by Michael Jackson's estate. Gaye's heirs not only accuse Thicke and "Blurred Lines" co-writers Pharrell Williams and "T.I." Clifford Harris Jr. of copying Gaye's song, but they also contend Sony-ATV failed to meet its responsibility to protect the copyright.
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Gaye family also contends Thicke's "Love After War" copied Gaye's "After the Dance"
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Robin Thicke, Pharrell Williams and rapper T.I. recorded the summer smash
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Musicologist report identified eight similarities in the two songs, counterclaims says
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Family suggest Thicke has "Marvin Gaye fixation"
Pharrell Williams
Pharrell Williams
The Gaye family contracted with Sony-ATV after the singer-songwriter's death to administer his music catalog, but it also represents @placeholder' songs, according to a counterclaim filed Wednesday in response to a lawsuit filed by Thicke, Williams and Harris.
Pharrell Williams
Pharrell Williams
"@placeholder and I were in the studio making a couple records, and then on the third day I told him I wanted to do something kinda like Marvin Gaye's 'Got To Give It Up,' that kind of feel 'cause it's one of my favorite songs of all time," Thicke reportedly said.
Got to Give It Up
"Pharrell and I were in the studio making a couple records, and then on the third day I told him I wanted to do something kinda like Marvin Gaye's '@placeholder,' that kind of feel 'cause it's one of my favorite songs of all time," Thicke reportedly said.
Robin Thicke
Thicke
Thicke
Robin Thicke
Thicke
"Pharrell and I were in the studio making a couple records, and then on the third day I told him I wanted to do something kinda like Marvin Gaye's 'Got To Give It Up,' that kind of feel 'cause it's one of my favorite songs of all time," @placeholder reportedly said.
Got to Give It Up
Maybe that's because it was originally a Marvin Gaye song ("@placeholder") and Marvin Gaye is ...
Marvin Gaye
Marvin Gaye
The family suggests that Thicke has a "@placeholder fixation."