Bradley Cooper reveals what it was like singing on stage in 'A Star Is Born': 'I was terrified'

Bradley Cooper is gearing up for the release of his highly-anticipated film, "A Star Is Born."

Cooper and his movie co-star, Sam Elliott, stopped by "Good Morning America" Wednesday and Cooper revealed what it was like singing on screen in front of a crowd at the Stagecoach Spotlight Tour.

"Willie Nelson let us go on before him," Cooper recalled. "We just hopped on the stage and I said, 'Hi everybody, we're going to shoot a movie. It's all about you. Thank you.'"

He continued, "I was terrified. We were all terrified, the whole crew. No one had really ever done that before."

In the film, Cooper takes on the role of Jackson Maine, a singer-songwriter and Lady Gaga's love interest. Elliott plays the older brother and manager of Cooper's character. Elliott said he and Cooper broke the ice during their first meeting.

"We finally got together and one of the first things he did, he played a tape for me of him working with a voice coach that he'd been doing for a number of months," Elliott recalled. "He said, 'This is going to sound a little weird' and it did sound a little weird because it sounded very much like me."

Elliott also gave props to Cooper, who not only co-wrote the screenplay, but had his directorial debut.

"Bradley set a tone that allowed all of us to trust him," Elliott said. "I think when you can trust the director and trust your fellow actors, the odds are you're going to get to the truth and I think that's why this film is so special."

Cooper said it was other film directors who inspired him along the way.

"I think just being a student and having people like David O. Russell and Clint Eastwood be so open about their process and it's all rhythm too," he said. "A love story, it should breathe because you have to see them fall in love."

"A Star Is Born" hits theaters this Friday.