Gaga, 32, who played a young singer in A Star Is Born, is now in the midst of a residency at the MGM Park Theater, where she started her run of shows in December.
"I even got you in-ears", Gaga told Cooper after the two embraced, describing the earphone-like monitors used onstage.
A Star Is Born tells the tragic love story of ME, played by Cooper, who helps Gaga's struggling artist Ally.
Stop-gap measure brings temporary end to government shutdown — IN Focus
But he maintained that Trump is ready to use emergency powers to secure the border if Democrats continue to balk at his demands. Democratic Senator Mark Warner and Republican Senator Rob Portman have introduced separate bills to prevent future shutdowns.
Galaxy S10 leaks reveal radical 'hole punch' camera and bezel-less screen
Expect things to kick off properly once the Galaxy S10 is out there and Samsung fans have nothing else to divert their attention. Photos of the Samsung Galaxy S10 have leaked , giving us another look at the upcoming flagship and its hole-punch display .
Zola and Hazard predict Higuain will be a big success at Chelsea
Sutton, promoting The Sportsman's flawless 10 game, said: "I think I know from my own experience that it's a big shirt to fill". Although only two league places now separate these teams, in truth the gulf between them is vast .
Sharing a picture of the performance on Twitter, one fan wrote: "As if Lady Gaga's spellbinding 2 hour greatest hits chronicling Enigma wasn't epic enough, the encore involved her pulling Bradley Cooper out of the audience to duet on Shallow". He then sat next to Gaga at the piano, hugging her as they sang the second chorus.
Lady Gaga fans weren't far from the "Shallow" on Saturday night. After the performance, he reportedly threw a hat into the crowd.
"I can't hear anything", he joked, telling the crowd, "Hello Vegas", before singing his verse in the Oscar-nominated song.
The song earned the singer, born Stefani Germanotta, an Academy Award nomination and a Golden Globe Award for best original song.