From T.I. And Usher To Justin Bieber And Jason Mraz, Taylor Swift Is The Queen Of Concert Duets

This weekend at Atlanta's Philips Arena, Taylor Swift was joined on stage for a pair of surprise duets. On Saturday, during the first of two sold-out shows, Swift shared the spotlight with Usher to perform his hit "Yeah!" and the following night got an assist from newly free T.I. Late in her show Sunday night, Swift introduced the rapper by singing the chorus to his song, "Live Your Life." He then joined her on stage to wild applause to perform his track while Swift sang the chorus – performed on the record by Rihanna – alongside him.

(Even stranger was the crowd backstage at Swift's Sunday night show in Atlanta. Not only was T.I. shooting the breeze before hitting the stage, but Nelly and Young Jeezy were there too.)

This isn't the first time a guest has joined Swift on her "Speak Now World Tour." The Grammy-winning country diva has been bringing her famous friends on stage to perform with her throughout her tour and rather than have them join her for one of her songs, Swift often lets her superstar guests shine and instead joins them for one of their songs.

Who else has partnered with the Speak Now superstar for a surprise concert appearance, read on to find out.

Jason Mraz

At another of Swift's series of sold out dates at the Staples Center, Jason Mraz joined her to perform his smash "I'm Yours." The crowd went nuts and the 20,000-person arena erupted into a spontaneous sing-along to the tune.

Justin Bieber

You want to hear an arena full of teenage girls lose their mind? Listen as Taylor Swift brings Justin Bieber on stage for a performance of his smash "Baby."

Nicki Minaj

Swift is a very vocal fan of Minaj, having given an impromptu performance of "Super Bass" during a radio interview in February (months before the track was released as a single). So it was fitting that when Minaj joined Swift on stage at LA's Staples Center in late August, the pair performed the hit.

Taylor Swift Nicki Minaj - Superbass by jenpokro

Hayley Williams

"Well, the thing about Nashville, one of the amazing things about it, is that there's so many friends here," Swift said during a September concert in the country music capital. "My friend Hayley has this band called Paramore…" With that, Williams took the stage for a duet of Paramore's hit "That's What You Get."

Hot Chelle Rae

Also in LA, Swift performed hot up-and-coming band Hot Chelle Rae's "Tonight Tonight" with the band, which will open for the 21-year-old singer on the Australian leg of her tour in early 2012.

Tim McGraw

It was something of a full circle moment when Swift hit the stage in Nashville with the man who inspired her first hit, Tim McGraw, to sing his track, "Just To See You Smile." During the same show, Swift managed to wrangle another country superstar into a collabo, exchanging verses with Kenny Chesney on his hit, "Big Star."