Lady Gaga Calls Tony Bennett 'Family' During Star-Studded 90th Birthday Concert: 'You Really Changed My Life'

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In celebration of Tony Bennett's 90th birthday, some of the biggest names in music got together for a tribute show that redefined what a career retrospective can look like with unmatched class, elegance and style.

Alec Baldwin -- doing his legendary Bennett impersonation in full prosthetic makeup -- was the unofficial emcee of the evening, which was filled with performances by the likes of Stevie Wonder, Bob Dylan, Michael Buble, and many others.

Lady Gaga, who collaborated with Bennett on a 2014 duets album, Cheek to Cheek, kicked the evening off with a flawless cover of Frank Sinatra's famous hit "The Lady is a Tramp."

WATCH: Lady Gaga Helps Tony Bennett Ring in 90th Birthday in Stunning Black Gown

The "Million Reasons" singer later took the stage again -- making her one of the only guests to perform twice -- to deliver a breathtaking rendition of "La Vie en Rose," which she crooned beautifully in perfect French.

While singing, Gaga and Bennett shared a sweet moment as Gaga smiled at the iconic singer -- who was seated in the audience, and returned the gesture by blowing her a kiss.

"You're my family, Tony," Gaga said, as she showed off her tattoo dedicated to Bennett, which she got back in 2014. "You really changed my life."

"You are indeed an icon, but for me, you're so much more than that," Gaga added after she sang, before introducing Elton John in a pre-recorded performance of his single "Can You Feel the Love Tonight."

Additional performers who turned out to honor Bennett with musical performances included Billy Joel, Leslie Odom Jr., and even Kevin Spacey, who famously played crooner Bobby Darin in the 2004 biopic Beyond the Sea.

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At the end of the night, Bennett took the stage himself, looking heathy and happy as he sang the most appropriate Sinatra standard possible: "The Best Is Yet to Come."

For more on the epic friendship between Gaga and Bennett, check out the video below.