Taylor Swift had big news for her fans Monday, and it wasn’t just a new song and album: The country darling has officially gone pop.

Her fifth release, 1989, out Oct. 27 and named for the year she was born, is her “first documented, official pop album,” she told the crowd of handpicked fans at the top of New York’s Empire State Building, where she hosted her much-hyped, half-hour Yahoo live stream Monday evening.

The goal for leadoff single Shake It Off was to create a song that sounded like “nothing I had done.” Produced by Max Martin and Shellback (the team behind other enormous Swift hits I Knew You Were Trouble and We Are Never Ever Getting Back Together), the unabashedly poppy anthem is inspired by a lesson that Swift learned in the two years since her last album, 2012’s Red. “People can say whatever they want about us, at any time,” she said. “The only thing we can control is our reaction to that.”

WATCH: Meet the many sides of Taylor in her video for ‘Shake It Off’

SONG OF THE WEEK: There’s nothing country about ‘Shake It Off’

EARLIER: Taylor Swift debuts ‘Shake It Off,’ reveals ‘1989’ album

Shake It Off is accompanied by an equally chirpy music video directed by Mark Romanek (Johnny Cash’s Hurt, Michael and Janet Jackson’s Scream videos). In it, the 24-year-old singer is flanked by ballerinas, gymnasts and twerking women.

Whether any of that will appeal to the country fans who made her a superstar remains to be seen.

“Does anyone still think of Taylor Swift as a country artist anymore?” says Rolling Stone contributing editor Anthony DeCurtis. “She’s very career-savvy, and I’m sure she and her handlers are convinced she can withstand any potential blowback. And I would agree.”

Says Jason Lipshutz, associate editor at Billboard, “I don’t think it’s Taylor Swift deserting the genre as much as it’s Taylor Swift trying something new.

“Her last album was based in country music, but it had a lot of bubblegum pop in it,” he says. “She’s always been a great storyteller, but she’s been trying her hand at pop music more and more.

“It’s kind of a complete transition that if you’ve been paying attention, you could see coming.”

But Gregg Swedberg, program director of K102 in Minneapolis, doesn’t believe country radio “will pay Taylor much attention this time.”

“I’m sure there will be some stations who will play it a couple of times, as she makes high-quality music no matter the genre,” he adds. “Taylor fans will love the new music, and it’s well known that her fans come from all formats.

“I hope she gets the country muse again soon, and we’ll gladly welcome her back whenever that is.”