As Kamala Harris prepared to deliver the biggest speech of her career, one of the year’s biggest rumours snowballed online and in the media about a potential surprise guest.

In an election campaign in which anything has seemed possible, a Democratic National Convention appearance by Beyoncé, whose song Freedom is the Harris campaign’s official song, seemed for a brief moment like it could be on the cards.

On Thursday, TMZ published a story with the headline “Beyoncé Performing at DNC final night!!!”, reporting “multiple sources in the know” had said she would “be the big surprise performer”.

The Hill posted a story headlined Beyoncé to perform at Democratic convention: Sources and also reported that Nick Hutchins, who works for the progressive firm Swing Left, had posted on social media saying he heard a band at the convention rehearsing Beyoncé songs, including “Cuff It”.

Florida representative Fentrice Driskell also posted video of the band performing a Beyoncé song.

Rolling Stone reported that, “According to two sources familiar with the matter, government officials, including Chicago Mayor Brandon Johnson’s office, local law enforcement personnel, and DNC organizers have been rushing to prepare for potential Beyoncé-related chaos in the Windy City – even if she does not end up showing up.”

Harris has used Freedom, the gospel-tinged anthem from Beyoncé’s 2016 album, Lemonade, as a prominent track on the campaign trail; soundtracking the video announcing Minnesota’s governor, Tim Walz, as her running mate, as well as several rally entrances. It’s the backbone of a campaign playlist that centres Black female artists, including Diana Ross, Aretha Franklin, Chaka Khan, Whitney Houston, Rihanna, Lizzo and Megan Thee Stallion.

There was a buzz over White House political director Emily Ruiz posting a bee emoji on social media hours before Harris’s speech. She replied to the tweet, saying “Sorry guys my 6 year old took my phone”. Beyoncé fans refer to themselves as the Beyhive.

Mitt Romney joked that “Contrary to fake news posts, I am not the surprise guest at the DNC tonight. My guess is that it will be Beyoncé or Taylor Swift. So disappointing, I know!”

MSNBC’s Katie Phang wrote, “I’m hearing that @Beyoncé has arrived at the United Center!”.

But as the night wore on, the rumour mill started to move in reverse.

A Harris-Walz Youth Team member at the DNC who had tweeted a post saying, in all caps, “Beyoncé just arrived” deleted it. The tweet was seen by several Guardian staff before it was removed.

The Hollywood Reporter, citing a representative for the singer, published a story as the convention began saying she “will not attend the 2024 Democratic National Convention”.

“Beyoncé was never scheduled to be there,” a representative for the singer told The Hollywood Reporter. “The report of a performance is untrue.”

And the Washington Post spoke to DNC organisers who said, in the Post’s words “there is no such special guest planned”.

In the end, a recording of Freedom was used to welcome Harris to the stage and to play her out at the close of the convention, as thousands of balloons fell gently down on to the attending delegates. Beyoncé herself did not appear.

TMZ later posted: “To quote the great Beyonce: We gotta lay our cards down, down, down ... we got this one wrong.”

Though her approval of Harris’s use of her song is seen as tacit endorsement, Beyoncé has not officially endorsed the Democratic presidential nominee, but has previously endorsed Democratic candidates, including Biden and Harris in the 2020 campaign. (Donald Trump’s campaign, which faces legal trouble for unauthorised use of music, has also used the song in videos posted to X, formerly Twitter.)

Beyoncé performed the Etta James standard At Last during Barack Obama’s first inaugural ball in 2009, and took on the national anthem for his second inauguration in 2013.

Along with her husband, Shawn “Jay-Z” Carter, she campaigned for Hillary Clinton in 2016, appearing with her at a rally in Cleveland days before the election as part of a celebrity blitz for the Democrats. “There was a time when a woman’s opinion did not matter,” she told the crowd of 10,000 people, urging them to vote. “I’m with her.”

Harris praised Beyoncé earlier this year on X, writing: “Thank you for reminding us to never feel confined to other people’s perspective of what our lane is. You have redefined a genre and reclaimed country music’s Black roots. Your music continues to inspire us all.”

The Harris campaign did not respond to the Guardian’s request for comment.