“I’ve never played this song live before, it’s one of my favorites,” Swift, 34, told the crowd in Melbourne, according to fan videos shared via social media. The singer sat at her piano in a yellow dress for the acoustic set — otherwise known as the surprise songs. (She also performed “Red (Taylor’s Version)” on the guitar.)

“You’re Losing Me,” a Midnights vault track, was initially available on the Late Night Edition of her 2022 record, which was sold as a CD at her Eras Tour stops in New Jersey last year. Swift finally brought the song to streaming after she was named Spotify’s 2023 Top Global Artist.

“I just wanted to say to anyone who listened to my music this year, anywhere in the world, thank you,” Swift wrote via Instagram in November 2023. “Getting named Spotify’s Global Top Artist in 2023 is truly the best birthday/holiday gift you could’ve given me.”

She continued: “I was trying to think of a way to thank you, and a lot of you have been asking me to put ‘You’re Losing Me (From The Vault)’ on streaming… so here you go! You can finally listen EVERYWHERE now

Fans were quick to speculate that the “You’re Losing Me” lyrics detail the end of Swift’s six-year relationship with Joe Alwyn. (Us Weekly confirmed in April 2023 that the two had split.)

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“I glared at you with storms in my eyes / How can you say that you love someone you can’t tell is dying?” Swift sings in the second verse. “I sent you signals and bit my nails down to the quick / My face was gray, but you wouldn’t admit that we were sick.”

Taylor Swift performs at Melbourne Cricket Ground on February 16, 2024 in Melbourne, Australia. Graham Denholm/TAS24/Getty Images for TAS Rights Management

Swift’s friend and longtime collaborator Jack Antonoff subsequently stirred the pot by revealing when the pair wrote and produced the song, fueling new fan theories.

“‘You’re Losing Me’ is out today, a very special track from the Midnights sessions that’s finally streaming!” Antonoff, 39, shared via his Instagram Story in November 2023, sharing a photo of Swift. “Written and recorded at home on 12/5/21 after Taylor ate these raisins.”

Neither Swift nor Alwyn have spoken publicly about the reason for their breakup. Swift briefly moved on with The 1975 singer Matty Healy before going public with boyfriend Travis Kelce in September 2023. Days before kicking off her Australian tour dates, Swift supported Kelce, 34, as he and the Kansas City Chiefs defeated the San Francisco 49ers in Super Bowl LVIII in Las Vegas.