CHICAGO (NewsNation Now)— Taylor Swift announced the release of her ninth studio album Thursday morning, just a few months after she surprise-dropped “Folklore.” The album is set to be released Friday.

“Ever since I was 13, I’ve been excited about turning 31 because it’s my lucky number backwards, which is why I wanted to surprise you with this now. You’ve all been so caring, supportive and thoughtful on my birthdays and so this time I thought I would give you something,” the singer tweeted on Thursday morning.

The album, “Evermore,” is the sister to her last album “Folklore,” Swift said. Evermore will stay in line with the folksong vibes, straying from the pop sound that Swift has become known for.

Her song “Cardigan” hit #1 on Billboard and stayed on the charts for 16 weeks after the surprise release in August.

Eleven tracks out of 16 hit the Billboard charts, with nine of them in the Billboard Top 10.

“To put it plainly, we just couldn’t stop writing songs,” Swift tweeted. “To try and put it more poetically, it feels like we were standing on the edge of the folklorian woods and had a choice: to turn and go back or to travel further into the forest of this music. We chose to wander deeper in.”

Swift also signaled that her future albums will sound much like Folklore and Evermore.

“There was something different with folklore. In making it, I felt less like I was departing and more like I was returning,” she said.

NewsNation affiliate KRON contributed to this report.