Lady Gaga shows off her acting talent in 'A Star is Born'. Picture: Warner Bros.

Lady Gaga has revealed she dressed in disguise to go and see 'A Star Is Born' in a public cinema, but she had to leave because she got so emotional.

The 'Million Reasons' hitmaker stars as Ally alongside Bradley Cooper's Jackson Maine in modern remake of the 1936 classic - which tells the love story of a fading rock star who launches his love interest's career - and has revealed she went incognito to a theatre to see it with members of the public, but was so upset by the "tragic" ending, she had to rush out.

She told the latest issue of Variety magazine: "Yeah, I snuck in.

"I sat through most of it. 

"I had to remove myself before the end. 

"The film moves me so deeply. 

"I feel so entrenched in the character that the second half of the film - without revealing what happens - is so emotional and tragic.

"I have to take myself out of it."

The 32-year-old singer - who recently got engaged to talent agent Christian Carino - wept when she first watched her acting debut too.

She said: "I cried the whole time, because I missed Jackson."

The 'Born This Way' hitmaker - who is tipped to win an Oscar for the role - admits that she was filled with "doubt" about whether she would be "good enough" for the big screen, but she soon realised from the reaction she received that she had no need to worry.

She said: "This has been a very transformative time for me. 

"As an artist, there's always a feeling of 'Am I good enough? Am I making something honest? Am I making something true?' There is a sort of stagnant sadness in me, wondering if I'm enough. "Today I did not see that. I saw something different. I saw a clarity. I saw a truth."