As Gaga reveals in a new interview with Apple's Zane Lowe, filming for the musical reboot early last year came as her close friend Sonja Durham succumbed to her long battle with cancer.
"It's very special," Gaga says of the performance of I'll Never Love Again, shot at Hollywood's Shrine Auditorium.
"On that day, my friend Sonja who had been battling cancers for years, her friend called me and I could hear (Sonja) moaning in the background. And they said she's not doing well and I thought she was dying, so I left the set.
"I can't believe I didn't even stop to see Bradley, and I got in my car and started driving, and I missed her by 10 minutes."
Gaga's voice broke as she recounted what happened in the room in the immediate aftermath of her longtime friend's death.
"I laid with her and her husband and stepson for a little while … then I looked her husband, her widower, in the eyes and said, 'I don't know what to do.' He said, 'You've gotta do what Sonja would want you to do.' She loved being a performer and she loved working in music," she said of Durham, who had worked as part of Gaga's team before her illness.
Incredibly, Gaga returned to set that day — and straight into filming her performance of I'll Never Love Again.
"She gave me a tragic gift that day, and I took it with me and went back to set, and sang that song for (Cooper's character) Jackson, and for her. On that very same day, within an hour," she said, praising Cooper for his handling of the situation.
"Bradley was so beautiful with me that day, he was so loving. He was like: 'You don't have to do it too many times, it's OK.' I was like, 'All I wanna do is sing, man, just let me sing.'"