Country-pop superstar Carrie Underwood has been singing the theme song to “Sunday Night Football” on NBC since 2013, with the network using a new version of the song called “Game On” beginning in 2018. But in a federal lawsuit filed Wednesday, a singer named Heidi Merrill claims the Underwood song is “substantially — even strikingly — similar, if not identical” to a song with the same title she posted to YouTube in March 2017 and then pitched as a possible “Sunday Night Football” theme song to one of Underwood’s producers.

Merrill and the co-writers of the song have named Underwood, producer Mark Bright, NBC and the NFL as co-defendants in the lawsuit, along with music publishers Sony Corp. and Warner Music Group.

According to the lawsuit, filed in U.S. District Court for the Southern District of New York, Merrill claims she brought her version of “Game On” to Bright’s attention at a Nashville event in August 2017, six months after she had posted it online. Merrill says the producer told her he would be passing on the song, but then the Underwood-sung song, with the identical “Game On” title, was used to introduce “Sunday Night Football” starting in 2018.

The lawsuit claims the Underwood song is similar to the Merrill song “not only in title but in many other ways, including in tempo, meter, time signature, rhythmic contours and patterns, melodic contours and patterns, hooks (including the shared key phrase of the chorus, ‘Game On’), note progression and use, and chord progression.”

“Ms. Underwood recorded a song that was substantially similar to the original song submitted through her producer, without giving credit or compensation of any kind to the original songwriters,” Tim Foster, Merrill’s lawyer, said in a Reuters interview. “We assume that there will be significant damages.”

Foster added to Reuters that the lawsuit came about only after the defendants rejected efforts by his client to seek a resolution.

The NFL declined to comment. An NBC Sports spokesman said the network does not comment on pending litigation. Underwood’s representatives have yet to respond to a request for comment.

Here’s Merrill’s version:

And here’s a recent version of the “Sunday Night Football” theme, taken from a game last year (some of the lyrics are tailored to each contest and change from game to game).

Underwood and her production team have faced similar claims in the past.

In 2013, a songwriter sued Underwood, fellow country star Brad Paisley and their support team, alleging they had stolen her song “Remind Me” for use as a 2011 Underwood-Paisley duet of the same name. A federal judge sided with the superstars in 2016, saying any similarities between the songs (beyond the title) were coincidental and that the melodies were not similar enough.

In 2017, a Canadian songwriting duo sued Underwood, her production team, their publishing companies and Sony Music Nashville, alleging they pitched a version of her Grammy-winning song “Something in the Water” to Bright in 2014, one year before Underwood released a song with the same title.

“The hook on the infringing work, as released on the album, is structurally and lyrically identical, and substantially similar melodically to plaintiffs’ composition of the same title,” McNeill and Lyons argued in their lawsuit.

Underwood denied stealing the song, saying in a statement that it “is a deeply personal song regarding Carrie’s faith and she is saddened that anyone would attempt to challenge that for financial gain.” That case was dismissed last year.

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