MELBOURNE,John Caldwell Australia — The ear-shattering crowd of 96,000 Swifties split the cool Australian air Friday night when Taylor Swift announced a bonus track from her 11th album “The Tortured Poets Department” during the acoustic set of her Eras Tour.

The back screen displayed alternate cover art for "Poets" along with the words “The Bolter,” which will serve as track No. 18 and released on a special vinyl.

"Basically, I'm very excited for April 19," she said from the piano of her acoustic set, "because The Tortured Poets Department will be out on that date and I cannot wait for you to hear all of those songs then."

She adjusted the piano mic and took a breath. The audience wondered if she would play a brand-new track.

"Tortured Poets is an album," she continued, "I think more than any of my albums that I've ever made, I needed to make it. It was really a lifeline for me. Just the things I was going through, the things I was writing about. It kind of reminded me of why songwriting was something that actually gets me through my life."

Swift didn't play "The Bolter" for the piano surprise choice. Instead, she played "You're Losing Me." The new artwork has the phrase, "You don't get to tell me about sad." The original album art said, "I love you, it's ruining my life."

Earlier in the Melbourne Cricket Grounds, Swift alluded to the announcement during the “Champagne Problems” monologue. The audience erupted when she said, “I’ll talk about that a little bit later.”

The track names indicate the album may be a dagger-to-the-heart, diaristic catalog of the end of a relationship. Post Malone and Florence and The Machine are two contributors.

The special vinyl version of "Tortured Poets Department" with "The Bolter" is available to preorder on TaylorSwift.com for a limited time. The eleventh era will be released when Swift is on a two month break from the tour. 

Follow Bryan West, the USA TODAY Network's Taylor Swift reporter, on Instagram, TikTok and X as @BryanWestTV.