Bradley Cooper admitted Eddie Vedder warned him not to make 'A Star is Born'.

Bradley Cooper

Bradley Cooper

The 43-year-old star directed, co-wrote and produced the musical drama - in which he also appears in the lead role of musician Jackson Maine - and he has revealed the input the Pearl Jam rocker had during research for the role.

He told Yahoo Entertainment: "I went up to Seattle and spent four or five days with him and I asked him 9,000 questions.

"And he gave me minor, little things that only musicians know about what to do, just aesthetically and the inner workings... He thought it was crazy I was going to do this movie. He was like, 'What? Bro, don't do that."

Cooper explained while Vedder certainly influenced the character, Jackson was also inspired by John Norman Howard, who was lpayed by Kris Kristofferson in the 1976 film, which itself was a second remake of the 1937 original.

Insisting it's not a riff on any specific recording artist, he added: "It was an amalgamation, on a subconscious level."

Meanwhile, Cooper and his co-star Lady Gaga - who is making her big screen debut in the project, which marks the former's first major foray behind the camera - have both admitted they were taking a huge risk.

He recently said: "There are certain projects where you can go, 'It didn't work out, but it's OK'.

"And there are others where it's like, 'Actually, that wasn't OK, and I took about five steps back.' This was one of those. If it didn't work, we both knew it was going to affect our careers."

Gaga agreed: "Things could have turned a bad corner."