Fans have been given their first look at Lady Gaga's debut feature film role, in the trailer for A Star is Born.
The film, directed by and starring Bradley Cooper, sees Gaga in the role of Ally, an aspiring singer helped into the industry by an older musician.
It's a remake of the 1976 Barbra Streisand and Kris Kristofferson film - itself a remake of two earlier versions, from 1954 and 1937.
Gaga said being in the film was a "dream come true and an honour".
The trailer, released on Wednesday, sees the Poker Face singer, known for her outrageous outfits, with a stripped-back look a world away from her stage persona.
It starts with Cooper, who plays singer Jackson Maine, performing in front of a huge audience - in scenes actually filmed on the Pyramid Stage at last year's Glastonbury Festival, where Cooper was on stage to introduce Kristofferson.
Gaga praised Cooper's singing abilities in her tweet.
It’s a dream come true and an honor to be a part of this incredible movie. Bradley's ability as a director, actor and musician is astounding. It’s called “A Star Is Born,” and I’m beyond thrilled for you to meet Jack and Ally. #AStarIsBorn https://t.co/L1rIawrzJ4— Lady Gaga (@ladygaga) June 6, 2018
Meanwhile, the screenwriter and director Joss Whedon was one of many people to be impressed by Gaga's acting prowess.
I don’t know if I’m interested in seeing Lady Gaga in “A Star is Born”— Joss Whedon (@joss) June 6, 2018
I don’t want to see anything that’s not Lady Gaga in “A Star is Born”, I’m just gonna shut my eyes till it’s out
Katy Perry said she was "screaming" at the trailer, while Lea Michele said she couldn't wait to see it.
I can’t this looks SO good so good so good!!!!! Wake me up when it’s October I can’t wait that long!!!! 🙌🏻 https://t.co/Sh7GYHsXfU— Lea Michele (@LeaMichele) June 6, 2018
Some are already suggesting that either Gaga - real name Stefani Germanotta - or Cooper, making his debut as a director, could be in line for an Oscar next year.
Gaga has composed new songs for the film, which sees the couple fall in love before experiencing struggles as Ally's fame rises, while Jackson's falls. The original songs have been written alongside Cooper and other artists including Mark Ronson.
Judy Garland appeared with James Mason in the 1954 version of A Star is Born, while the 1937 film starred Janet Gaynor and Fredric March. The first two films were set in Hollywood, before the action moved to the music industry for the Streisand film.
A Star is Born is released by Warner Brothers in October.