Everything Has Changed

Taylor wrote this duet with British singer-songwriter Ed Sheeran whilst they were sitting on a trampoline. She recalled to MTV News: "We, for real, [were] sitting on my trampoline in my backyard cause we had been writing a song and I was like, 'Hey, I just got a trampoline. You want to see it?' And so, he brought the guitar for some reason."

Taylor added: "We ended up writing an entire song out there. For portions of the song, [we were bouncing around] 'cause it's a trampoline and it's fun, and the combined maturity level of both of us is 8 years old."

Though Sheeran comes from a folk background and Swift a pop-country one, the English singer-songwriter told MTV News their partnership worked as they have a lot in common. "Well, I don't really write so much with other artists," he said. "Like the Taylor session, when we got together and wrote was the second time I've ever gotten with another singer/songwriter and written a song with them. So it wasn't actually too hard of an adjustment. We're very much alike musically and it worked out well, I think."

Ed Sheeran is one of several songwriters that Swift reached out to write with her on Red. She told Billboard magazine that the people she chose to collaborate with were ones who inspired her. "You look at someone like Ed Sheeran," she said. "He comes from such a sincere place as a writer, and his songs move you in every direction emotionally. That's something I was so inspired by I ended up calling him."

The song was produced by Butch Walker, who once covered Swift's "You Belong With Me."

Regarding the song's meaning, Taylor told Digital Spy: "It's about falling in love. It's about meeting someone and all of a sudden your entire perspective on the world changes - you're thinking for two, instead of one."

Asked by The Sun how Sheeran and her originally met up, Swift replied: "We had both reached out to each other's camps at the same time. I showed up at his hotel in Arizona and we just wrote songs all day. Then he came and hung out at my house in LA and we spent all night sitting on the kitchen floor laughing, writing songs and harmonising."

Swift first came across Sheeran when she heard one of his singles while traveling abroad. "I was in Australia when I first saw Ed Sheeran's music video for 'Lego House' and I was so blown away by his voice that I found a way to get his album, the entire album, even though it was not on sale in the U.S. yet," Swift told MTV News. "And became a huge fan."