The parties involved in a huge legal fight over the English language's most popular song, "Happy Birthday to You," have arrived at a settlement. A judge's order released on Wednesday revealed the deal and vacated a trial that was set to begin on Dec. 15. According to a source, once the settlement is finalized, "Happy Birthday" will be in the public domain beyond dispute.

The lawsuit began in 2013 when a film company working on a documentary about the "Happy Birthday" song refused to make a $1,500 synchronization license fee payment to Warner/Chappell Music. The proposed class action aimed to free the song from copyright control by showing that a song that traces its origins to a 19th century schoolteacher named Patty Smith Hill and her sister Mildred Hill was really in the public domain.

The dispute centered on how the Hill sisters transferred control of the song to Clayton Summey, how the song was published in books and sang in classrooms in the subsequent decades, and whether a 1935 copyright registration included lyrics.

In September, a federal judge ruled that Warner/Chappell Music never acquired a valid copyright to the lyrics.

The plaintiffs aimed to recover a substantial fortune for licensing money collected dating back to the 1940s. The song has been reported to reap about $2 million a year.

Before coming to a settlement, Warner/Chappell wanted the judge to reconsider his September ruling or authorize an immediate appeal. The music publisher argued the judge should have applied more presumption to the validity of the 1935 copyright that it had obtained from Summey's company. Meanwhile, a charity organization stepped forward in an effort to intervene, identifying itself as being co-founded by Hill and arguing that it might be the real owner of the "Happy Birthday" copyright. A trial would have examined this issue. The plaintiffs have argued that any ownership to the lyrics was abandoned or foreclosed by divestive publishing.

The parties have resolved this mess, but for now, terms of the deal haven't been released. That may be be forthcoming at some point, but in the meantime, it appears as though "Happy Birthday" is in public domain. That means, TV and film producers and others will never have to pay to use "Happy Birthday" again.

A Warner/Chappell spokesperson commented, "While we respectfully disagreed with the Court's decision, we are pleased to have now resolved this matter."

The attorneys representing the plaintiffs are Randall Newman, Mark Rifkin, Janine Pollack, Beth Landes and Giti Baghban. Warner/Chappell's legal team was led by Kelly Klaus at Munger, Tolles & Olson.