Evermore, on Thursday night at midnight ET. The new project is a "sister record' to Swift's eighth studio album, Folklore, she writes. Swift dropped "To put it plainly, we just couldn’t stop writing songs," Swift writes on Instagram. "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." The new music arrives just days before Swift's 31st birthday on Sunday (Dec. 13). "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," Swift writes in a subsequent post. "You’ve all been so caring, supportive and thoughtful on my birthdays and so this time I thought I would give you something! I also know this holiday season will be a lonely one for most of us and if there are any of you out there who turn to music to cope with missing loved ones the way I do, this is for you."