When "Folklore" was first released in the summer of 2020, Taylor credited her co-writers on Instagram. 

"I wrote and recorded this music in isolation but got to collaborate with some musical heroes of mine; Aaron Dessner (who has co-written or produced 11 of the 16 songs), Bon Iver (who co-wrote and was kind enough to sing on one with me), William Bowery (who co-wrote two with me) and Jack Antonoff (who is basically musical family at this point)," she noted in the caption of one of her posts.

She tagged all of her co-writers, except for William Bowery. Because the other collaborators on the album were big, recognizable names, many began suspecting that Taylor was using the name William Bowery to hide the identity of the real writer. Plus, when people searched the name, it yielded no past songwriting results. 

One popular theory that gained a lot of traction online was that William Bowery was really Joe Alwyn — especially because the name itself held clues about the couple. 

Joe's grandfather, William Alwyn, was a composer, and Taylor has hinted in her past lyrics that she first really connected with Joe at the Bowery Hotel in New York City. 

This idea was further fueled because Taylor herself has a track record of using a pseudonym. She worked on the 2016 song "This Is What You Came For," which was released by her then-boyfriend Calvin Harris and Rihanna. 

Instead of receiving credit under her name, Taylor aimed to stay anonymous as Nils Sjöberg. When the news was revealed, some fans wondered if she had worked on other tracks before with a fake name.

Taylor confirmed in her Disney+ documentary, Folklore: The Long Pond Studio Sessions, that her boyfriend, Joe Alwyn, used the pseudonym William Bowery to work with her on the album. 

While speaking with her other writers, Aaron and Jack, Taylor noted that listeners were wondering who William Bowery could be.

"There's been a lot of discussion about William Bowery and his identity, because... it's not a real person," she shared in the documentary. "So, William Bowery is Joe... as we know."

After revealing who William is, Taylor explained how she got Joe to help her on the album.