Taylor Swift & Miley Cyrus: Sing Out Sisters!

The teen singing sensations hope their Grammy performance will be just as great as their one-day rehearsal

If their rehearsal is any indication of things to come tonight, Taylor Swift predicts her Grammy performance with Miley Cyrus will be something special.

"We rehearsed for just a day," Swift told me last night at Clive Davis and the Recording Academy’s pre-Grammy party at the Beverly Hilton hotel. “The rehearsal actually went off without a hitch, so we’re pretty psyched about it."

Swift said it was her and Cyrus’ idea to perform “Fifteen,” a track from Swift’s most recent album, Fearless.

"They always love collaborations," Swift said of the Grammy producers. "They always sort of suggest that you present them with a collaboration that you think makes sense. So Miley and I had always been talking about 'When can we sing together? It would be so cool to sing together.' So we came to the Grammys and said, ‘What about this song, "Fifteen"? It really applies to us.' "

It certainly does apply. The Swift-penned tune is about life's first kisses, first loves and self-discovery. Those are pretty fresh experiences for Ms. Swift and Ms. Cyrus because, remember, they’re only 19 and 16, respectively!

They broke the news of the collaboration last week with Ryan Seacrest.

Swift and Cyrus aren’t the only two teaming up tonight. The Jonas Brothers will hit the stage with Stevie Wonder (I’m told they became friendly because Wonder’s kids are JoBros fans). Adele and country group Sugarland are another matchup, as are freshly minted collaborators Justin Timberlake and T.I., among others.