LOS ANGELES — A jury awarded Marvin Gaye’s children nearly $7.4 million Tuesday after determining singers Robin Thicke and Pharrell Williams copied their father’s music to create “Blurred Lines,” the biggest hit song of 2013.

Marvin Gaye’s daughter Nona Gaye wept as the verdict was being read and was hugged by her attorney, Richard Busch.

“Right now, I feel free,” Nona Gaye said after the verdict. “Free from ... Pharrell Williams and Robin Thicke’s chains and what they tried to keep on us and the lies that were told.”

The verdict could tarnish the legacy of Mr. Williams, a reliable hit-maker who has won Grammy Awards and appears on NBC’s music competition show “The Voice.”

The Gayes’ lawyer branded Mr. Williams and Mr. Thicke liars who went beyond trying to emulate the sound of Mr. Gaye’s late-1970s music and copied the R&B legend’s hit “Got to Give It Up” outright.

“They fought this fight despite every odd being against them,” Mr. Busch said of the Gaye family outside court.

Mr. Thicke told jurors he didn’t write “Blurred Lines,” which Mr. Williams testified he crafted in about an hour in mid-2012.

Mr. Williams told jurors that Mr. Gaye’s music was part of the soundtrack of his youth. But the seven-time Grammy winner said he didn’t use any of it to create “Blurred Lines.”

Mr. Gaye’s children — Nona, Frankie and Marvin Gaye III — sued the singers in 2013 and were present when the verdict was read.

The verdict may face years of appeals.

“Blurred Lines” has sold more than 7.3 million copies in the U.S. alone, according to Nielsen SoundScan figures. It earned a Grammy Awards nomination and netted Mr. Williams and Mr. Thicke millions of dollars.

The case was a struggle between two of music’s biggest names: Mr. Williams has sold more than 100 million records worldwide during his career as a singer-producer, and Mr. Gaye performed hits such as “Sexual Healing” and “How Sweet It Is (To be Loved by You)” remain popular.

During closing arguments, Mr. Busch accused Mr. Thicke and Mr. Williams of lying about how the song was created. He told jurors they could award Mr. Gaye’s children millions of dollars if they determined the copyright to “Got to Give It Up” was infringed.

Howard King, lead attorney for Mr. Williams and Mr. Thicke, told the panel that a verdict in favor of the Gaye family would have a chilling effect on musicians who were trying to recreate a genre or homage to another artist’s sound.

Mr. King denied there were any substantial similarities between “Blurred Lines” and the sheet music Mr. Gaye submitted to obtain copyright protection.

Mr. Williams has become a household name — known simply as Pharrell — thanks to his hit song “Happy” and his work as a judge on the “The Voice.” He wrote the majority of “Blurred Lines” and recorded it in one night with Mr. Thicke. A segment by rapper T.I. was added later.

Mr. Williams, 41, also signed a document stating he didn’t use any other artists’ work in the music and would be responsible if a successful copyright claim was raised.

Mr. Thicke testified he wasn’t present when the song was written, despite receiving credit.

The trial focused on detailed analyses of chords and notes in both “Blurred Lines” and “Got to Give It Up.”

Jurors repeatedly heard the upbeat song “Blurred Lines” and saw snippets of its music video, but Mr. Gaye’s music was represented during the trial in a less polished form. Jurors did not hear “Got to Give It Up” as Mr. Gaye recorded it, but rather a version created based solely on sheet music submitted to gain copyright protection.

That version lacked many of the elements — including Mr. Gaye’s voice — that helped make the song a hit in 1977. Mr. Busch derisively called the version used in court a “Frankenstein-like monster” that didn’t accurately represent Mr. Gaye’s work.

An expert for the Gaye family said there were eight distinct elements from “Got to Give It Up” that were used in “Blurred Lines,” but an expert for Mr. Williams and Mr. Thicke denied those similarities existed.

Mr. Gaye died in April 1984, leaving his children the copyrights to his music.

First Published: March 10, 2015, 11:00 p.m.