Miley Cyrus, Taylor Swift Talk Grammy Duet

'A lot of girls are inspired by us, so this song is us giving our advice,' Miley tells Ryan Seacrest.

[artist id="2389485"]Taylor Swift[/artist] and [artist id="2408193"]Miley Cyrus[/artist] are giddy about their big duet at Sunday's Grammy Awards. Swift said she knew when she was conceptualizing her performance for the show, she had to get Cyrus onboard.

"We all came to the consensus, 'Wouldn't it be cool if Miley was up there too?' " Swift told Ryan Seacrest when she and Cyrus called into his radio show on Tuesday morning (February 3). "And she said yes, and we're really excited about it."

The girls will be performing Swift's song "Fifteen," so the 19-year-old Swift talked a little bit about how the song came to be. "Well, it's a song I wrote about freshman year of high school. It was the last year of my life I thought I knew everything," she explained. "I had my first boyfriend when I was 15. I'm glad I was able to put it into words."

"The lyrics are very inspiring," Cyrus added about the song. "A lot of girls are inspired by us, so this song is us giving our advice. ... This song is pretty perfect for the Grammys."

While Swift was doing more traditional things when she was 15, Cyrus was busy working when her birthday rolled around. "I was on tour when I turned 15. It was different," she said. "You can be touring the world with the Jonas Brothers, or you can be in high school. I think you're going through the same things."

Another hot topic for the girls was how Cyrus recently traded in her Porsche for a more environmentally friendly Prius. "The Porsche is really hard to drive," she said. "I thought I could drive that thing. I got in it and was like, 'Hold the phone, this thing is huge!' "

Will Lil Wayne grab all the gramophones? Is Katy Perry going to tell her girl rivals to kiss off? Can Coldplay march off with a win? MTV News is all over the 51st Annual Grammy Awards, so stay tuned for interviews, analysis and more before, during and after the big night, Sunday, February 8.