Taylor Swift has become one of the biggest (and most controversial) working pop stars, and these days, it's easy to forget her beginnings were in country music. The singer doesn't shy away from her musical past, and Taylor Swift's surprise performance in Nashville on Saturday, March 31 was a return to her roots. Swift stopped by the city's Bluebird Cafe, the small and legendary performance space where she was discovered, for an impromptu concert.

As reported by The Tenessean, she was joined onstage by Craig Wiseman, an acclaimed country songwriter, who in addition to Swift has worked with Dolly Parton, Tim McGraw, and Faith Hill. Dressed in a plain turtleneck and hair pulled back, Swift revisited old songs from her catalog and told stories about her early days working in music.

According to The Tennessean, fans had no idea Swift would perform, and only about 50 people were at the event. The small crowd didn't stop the star from belting some of her early hits, including "Love Story" and "You Belong With Me" as well as some of her recent pop songs, like "Shake It Off." The Tennessean reported the intimate performance was filmed to be included in an upcoming documentary honoring the Bluebird's 35th anniversary. The star was sure to note the venue's significance to her life and career.

"I wanted to say a big thank you to the Bluebird Cafe," Swift told the audience, according to Yahoo News. "I think any songwriter in town would echo my sentiments and say that this is kind of the only place where this exists. This particular place where you get to come and hear the writer's take on the songs they've put out into the world."

In addition to the Bluebird, Nashville as a whole is an important city for Swift. Visiting is a return home for the singer - when she was 10, she persuaded her parents to move to the city so she could pursue music. She still has several homes in the city, and it's where her family resides. While on stage at the Bluebird, she credited Nashville for teaching her some of the most important lessons about songwriting. The main lesson was the song "If there's truth in it, don't over think it," she said, according to the publication. "It can be the same three chords over and over again."

Wiseman is a legend in country music, and the two have known each other since the singer's early career. However, he may not have had as big a role in her music as some people might assume. According to The Tennessean, one of the stories the musicians told was Swift's writing process for "Love Story," which the studio sent her to Wiseman to co-write. When she played him an early version of the song, he didn't get it. They penned a different song, but Swift went home and changed it back. "I couldn't stop thinking about the idea," Swift told the audience. "I thought there was something to it. I really liked it." The songwriter reportedly seemed embarrassed that he almost stopped such a mega-hit from being recorded, but it was all in good fun and the two performed the song for the audience.

The two performers also told stories about CMT afterparties, where Swift and Ed Sheeran used to drink Fireball shots. On Saturday, Wiseman reportedly took out a gift bag with tiny bottles of Fireball, and the performers took shots of whiskey. "For old-times sake," Wiseman told the crowd before they broke into another song, according to The Tennessean. Swift performed "Better Man," a song she wrote for the country group Big Little Town. The song went on to hold a #1 position on the Billboard charts, and the experience was special for Swift.

"When I would play writers nights ... I didn't have the experience of a writer writing something and then it going out into the world and you hearing it from someone else's perspective until recently," Swift explained to the Bluebird audience, according to The Tennessean. "Little Big Town gave me the opportunity to feel that way. To be at the Bluebird and play a song you've maybe heard on the radio. I will always be forever grateful to them for that."

Swift's fans were freaking out about the performance online, and took to Twitter to share their excitement.

This fan couldn't believe the performance was real. A few people on Twitter suspected the whole performance was an April Fools joke, but there was video footage to prove it happened.

The throwback was making some longtime fans emotional.

Swifties were in disbelief that the performance had happened, and tried to picture what it would be like to be at the small performance with such a major star.

Swift's latest album Reputation is a pop album, and these days the singer might not be performing much country music on an arena stage. But it's clear that her recent change in genre hasn't diminished her appreciation for country and folk music, and her appearance at the Bluebird on Sunday was a return to her musical roots. Fans were living for this throwback moment, but only time will tell if the star will revisit her early discography again soon.