The Swifties are sleuthing again — and this time, they found a nugget about unaccounted time in the stud!o.

On Tuesday, September 18, Swift’s longtime friend and producer, Jack Antonoff posted an tribute to Electric Lady Studios — the famed New York City recording studio where the pair have crafted some of Swift’s biggest hits. Antonoff, 40, captioned the post with a heartfelt tribute to the studio and the music he’s created there.

“my room upstairs at ELS. everything is possible in here and i miss it when im gone,” the Bleachers musician wrote. “spend my days and nights in this small room dreaming about how this music will hit the stage – spend my time on stage honoring what’s happened there while saving a piece of the show to bring back with me into this room.”

In the Instagram carousel swipe, fans noticed a black and white picture of Swift, 34, with producer Sounwave dated December 21, 2023. Sounwave collaborated with the 14-time Grammy winner on three tracks from her 2022 album Midnights; “Glitch,” “Karma,” and “Lavender Haze.” However, this photo was seemingly taken after she recorded Midnights. Swift’s 2024 album, The Tortured Poets Department, does not credit Sounwave, which leaves fans wondering what the trio was working on that day in the studio.

Speculation is in full swing as fans took to X, formerly known as , to share their theories. Many people thought this either meant Swift’s 12th studio album or Reputation (Taylor’s Version) was in the works.

“since sounwave didn’t work on ttpd, and the date says december…. she’s never not working omg dare i say this is ts12,” one user tweeted.

“She already turned in TTPD too, so this gotta be something new!!!! I think the rep tv vault tracks are done (unless she wants to add another) or this is for TS12!?! I can’t wait for it now, haha,” another individual commented.

Fans quickly pointed out that this wasn’t the first time they had seen this picture, as Sounwave posted it congratulating the pop star after she had accepted her award for Album Of The Year at the 2024 Grammys.

“This isn’t a new pic but it’s weird he posted it now” someone commented with the eye emoji.

Others brought up how Kendrick Lamar was reportedly also at Electric Lady Studios that day. While Lamar was featured on 1989 (Taylor’s Version), that album came out two months prior in October 2023. Sounwave has also frequently collaborated with Lamar, so the possibilities as to why everyone was at the studio that day are endless.

“Taylor Swift, Kendrick Lamar, and Sounwave were in the studio together on December 21st, and none of them were involved with TTPD,” one fan wrote via X.