In the music industry’s most closely watched copyright case, a federal appeals court on Wednesday upheld a jury’s finding that Robin Thicke’s song “Blurred Lines” infringed on the copyright of Marvin Gaye’s “Got to Give It Up.”

When the case went to trial in 2015, it became a flash point in the music industry over the limits of copyright. The family of Gaye, who died in 1984, argued that “Got to Give It Up” was copied without permission, and that it had helped make “Blurred Lines” the biggest hit of 2013.

Lawyers for Mr. Thicke and Pharrell Williams, who helped write and record the song, disputed that claim, and in the wider music industry, many worried that suit went too far in trying to protect generic elements of a song’s style and “feel.”

A victory, opponents of the case warned, could lead more litigation and have a chilling effect on creativity. Since the dispute over “Blurred Lines” began, there have been several prominent settlements over credit and royalties. For example, even before the “Blurred Lines” verdict was announced, Sam Smith willingly shared credit for his hit “Stay With Me” after Tom Petty said it sounded like his song “I Won’t Back Down.”