Taylor Swift’s performance on Saturday night in New Orleans featured some unexpected moments. Dressed in orange, the artist informed the audience that she was altering the routine of her surprise set. Instead of one of her own hits, she planned to perform a song by her friend, Sabrina Carpenter.

“Tonight, I’m going to do something totally different by singing a song that isn’t mine, but from someone I truly admire,” she told the crowd of 65,000 before beginning to play “Espresso” by Carpenter. After a few lines, she paused.

“You love that song as much as I do, right?” Swift asked, grinning. “I know I’m rambling, but I’m really proud of Sabrina and everything she’s accomplished this year.”

The audience erupted in cheers at the Caesars Superdome when Swift retrieved her phone from a crew member and put Carpenter on speaker.

“I’m in a really loud place, here in New Orleans on the Eras Tour,” Swift said into the phone. “I just wanted to let you know I sang a bit of ‘Espresso’ and everyone sang along. We all love you so much! What are you up to? Why aren’t you with us?”

Carpenter replied, “I’m in a place where everyone is screaming really loud.”

“I’m also surrounded by screaming crowds,” Swift responded. “Can you get to the stadium quickly? How long would it take?”

“Probably just five seconds,” Carpenter said. The crowd roared and held its breath as Carpenter appeared on the elevated platform, wearing a white dress.

Swift performed an acoustic rendition of “Espresso,” harmonizing with Carpenter.

“Holy s***, New Orleans!” Carpenter exclaimed after the first chorus.

“Can I take this one?” Swift asked, referring to the opening line of the second verse, “I’m working late, cause I’m a singer.” She then transitioned into a segment of her song “Is It Over Now?” from “1989 (Taylor’s Version)” followed by “Please, Please, Please” from Carpenter’s latest album.

“She had literally one day off,” Swift noted at the end of the trio of songs, “It’s incredible she came to join us. Let’s give a big cheer for Sabrina Carpenter!”

Carpenter made her way down the catwalk and then exited the stage.

Swift then moved to the piano to perform a medley of “Hits Different” from “Midnights” and “Welcome to New York” from “1989 (Taylor’s Version).”

The singer-songwriter has one more concert scheduled in New Orleans before finishing the tour on December 8 in Vancouver, Canada.