Watch Ariana Grande reunite with her 'Victorious' costars 6 years after the show ended to perform songs from the series

• Ariana Grande reunited with "Victorious" costars Elizabeth Gillies and Matt Bennett during her concert in Atlanta, Georgia, on Tuesday.
• The stars sang "I Think You're Swell" and "Give It Up" from the Nickelodeon show, which lasted from 2010 to 2013. 
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"Victorious" costars Ariana Grande, Elizabeth Gillies, and Matt Bennett reunited six years after the Nickelodeon show ended to sing popular tracks from it. 

Grande, who rose to fame as Cat Valentine on the sitcom that lasted from 2010 to 2013, performed in Atlanta, Georgia, on Tuesday evening as part of her Sweetener World Tour. She surprised fans by bringing out Gillies (Jade West) and Bennett (Robbie Shapiro) to perform two songs. 

Bennett played "I Think You're Swell" from season three's episode titled "The Blonde Squad," which his character sang to Cat after a boy broke up with her because he preferred blondes. 

You can see part of the rendition in the videos below, which were captured by @arianaxgiaw.

Prior to Grande and Gillies' duet of "Give It Up" from season one, The "7 Rings" singer introduced her costar as "the baddest b---- in the world" and one of her "best friends."

You can see a video of their performance shared by @intoyoukelsea below (warning: there is explicit language).

Gillies also shared a black-and-white video of them belting out the song. 

She went on to join Grande and her dancers onstage for "Thank U, Next," dressed in a red "Mean Girls"-inspired dress.

All three stars walked off the stage together, too.

The audience also sang along to the "Victorious" theme song, "Make It Shine."

At one point, Bennett sang "Make It Shine" with the fans in the crowd. Grande posted a video of the moment on her Instagram story and tagged her fellow costars, Victoria Justice (Tori Vega), Leon Thomas (Andre Harris), Avan Jogia (Beck Oliver), and Daniella Monet (Trina Vega).

Afterward, the stars shared photos and videos from the night. 

"the most special show to me yet. truly. love u. this was too much to process and don't know what to say yet but so grateful and thrilled. love u forever @LizGillies @MattBennett," Grande tweeted.

The singer also shared a photo of the trio together and Bennett jokingly called them "the new Beatles."

Gillies, who currently stars on The CW's "Dynasty," wrote: "Still can't process. Last night blew my mind. Love you, @ArianaGrande. Love you too, @MattBennett!! We did it!!"

Gillies and Bennett also praised each others' performances. The latter star also called it"One of the best nights of my life."

Prior to "Victorious," Grande and Gillies met while starring on the Broadway show "13." They met Bennett on the set of "Victorious" and remained close friends after the show ended in 2013. Gillies, Bennett, and Monet all appeared in Grande's music video for "Thank U, Next." Most recently, Bennett and Thomas attended Grande's Halloween party.

• Read more:
• THEN AND NOW: The cast of 'Victorious' 9 years later
• 52 photos that show Ariana Grande's dramatic style evolution, from Nickelodeon teen to global phenomenon
• Ariana Grande lets Miley Cyrus and Lana Del Rey do all the work in a new music video for the 'Charlie's Angels' reboot

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