Ahead of the Oscars, Bradley Cooper says Las Vegas duet with Lady Gaga was "just to see" if he'd be "horrendous"

Neal Preston

(LOS ANGELES) -- Now that Lady Gaga and Bradley Cooper are officially going to sing "Shallow" at the Oscars, Cooper says that -- unlike his surprise performance with Gaga in Las Vegas -- he really needs to start rehearsing.

Speaking to Entertainment Tonight, Cooper says when he sang with Gaga at her Enigma residency show in Las Vegas a few weeks ago, "I didn’t have any preparation. That was just to see.”

Cooper says he and Gaga pulled the performance together in two days.

He explains, “I’d thought about it and called [her and said] maybe I’d go to the show and then I knew she was singing 'Shallow' for her finale. And I thought, 'I don’t know, maybe if she wants to bring me up, let’s see if it’s not horrendous.'”

He adds, "That was an amazing experience. But no, I want to work and, like, rehearse [before the Oscars].” 

To that end, Cooper is hoping to get back together with his vocal coach, Roger Love, who helped him create Jackson Maine's singing voice for A Star Is Born.

“I couldn’t sing before this movie and so, in terms of being able to sing in front of people, it’s very nerve-wracking. It’s not easy what they do,” he tells ET. “We worked tirelessly [to prepare for the movie]."

Cooper says he's already called Love to arrange some rehearsal time, but he'd better start soon: The 91st annual Academy Awards air February 24 on ABC.

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