Jack Antonoff Shares Insight Into the Making of Taylor Swift's 'New Year's Day'

Out of all the producers Taylor Swift teamed up with for her new album Reputation, one was the indie-pop favorite collaborator Jack Antonoff.

While Antonoff fronts his own band, Bleachers, he also is busy in the studio working with artists like Lorde and St. Vincent to bring their latest albums to life, too.

After Swift performed one of her Antonoff-co-written songs on Monday night’s Tonight Show Starring Jimmy Fallon to an emotional reception, the producer took to Twitter to share a little bit of the back story of the piano-driven ballad “New Year’s Day.”

“Taylor doing New Year’s Day on Fallon was beautiful,” Antonoff wrote. “That song means a lot to me. Happened so quickly at my apartment. We texted the next morning to make sure it wasn’t a dream.”

It’s the only ballad and the final track on the much-hyped album, detailing the decaying glitter of the day after a big party — and the tender nostalgia of everyday, through-thick-and-thin love. With specific references that paint a vivid, recognizable picture — “Girls carrying their shoes down in the lobby / Candle wax and Polaroids on the hardwood floor” — it might also be one of her most relatable tracks on Reputation.

Write to Raisa Bruner at raisa.bruner@time.com.