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View photos Taylor Swift and Liz Rose at the 58th Annual BMI Country Music Awards in Nashville (photo: Rick Diamond/Getty Images for BMI) More

When Taylor Swift was first rising to stardom, and even for a few years afterward, there were a lot of naysayers who refused to believe a girl that young had that kind of songwriting talent. They looked at the credits on her albums and came to an easy conclusion: Clearly, Liz Rose, her decades-older co-writer, was the genius behind the throne.

"I know," says Rose now, remembering the time when Taylor haters were jumping to give her all the credit. "Look at those lyrics. Those are the lyrics of a 13-, 14-, 15-, 16-, 17-, 18-year-old. We certainly weren't writing 50-year-old Liz Rose songs — or 40-year-old, or however old I was then. I don't think like that! It's so funny to me that people could imagine that."

But there's no mistaking what an integral role Rose played in Swift's early success. The Music Row stalwart co-wrote seven of the songs on the singer's 2006 debut album, including her breakout singles, "Tim McGraw" and "Teardrops on My Guitar." For the follow-up, Fearless, released two years later, Rose collaborated on four songs, including the title track, "White Horse," and arguably one of the greatest pop singles of all time, "You Belong With Me."

Suddenly, a then-fortysomething mom improbably found herself as the voice of tween and teen America. Or, to be more accurate, its channeler.

Rose could hardly be humbler when she describes how her co-writing with Swift has worked. She's willing to accept far more credit when it comes to the other collaborations that have led to hit singles — such as "Crazy Girl," the No. 1 country hit for the Eli Young Band that won her an ACM Award last year for Song of the Year. When it comes to Swift, Rose swears that the ideas always sprang directly from the then-curly head of the young star, and that her primary function was to act as a conduit.

"The reason it worked is that I didn't get in her way," Rose says. "With Taylor, it really was editing. That's never anything that she said — that's just how it was! At some point I wondered if I was selling myself short by saying that, because songwriting is songwriting. But with her, that's really what I do, and it's unlike the way I've written with anybody else before or since. A lot of it with Taylor was editing and moving this there and saying, 'Well, what if we said it like this?' I can remember times when I would try and throw out an idea for a new song: 'How about we write this?' And she would just go, 'Yeah, I don't think so. Go and write that with somebody else.' Because Taylor always wanted to write her songs. And there was always so much going on in her brain, you just had to help her get it out and get it down. She always has a reason behind why she's writing something. She's lived it or felt it. She's not making it up."

Rose's favorite of the songs they wrote together was the last one they did, "All Too Well," which appeared on 2012's Red… a sad ballad that is widely believed to memorialize Swift's romance with Jake Gyllenhaal. "There is a very raw emotion in 'All Too Well' that still hits me when I hear it. With that song, when we got together, she had it all in her brain, and it was probably 10, 12, or 15 minutes long! She had a story to get out, so we just sat down and started going through it piece by piece, and as she sang all these things, I just wrote down what I thought were the important pieces that hit." (Maybe when Swift is Rose's age, we can get a boxed-set reissue of Red that includes the unexpurgated eight-verse version.)