Watch: Stars, Including Lady Gaga, Come Out for LA Premiere of Bradley Cooper's 'Maestro'

On the heels of scoring four Golden Globe nominations, the stars of Bradley Cooper's Leonard Bernstein biopic "Maestro" turned out in a big way to celebrate the film's Los Angeles premiere at the Academy Museum of Motion Pictures.

Star, director, and co-writer Cooper attended with his adorable six-year-old daughter, but it was the reunion between Cooper and his "A Star is Born" co-star Lady Gaga that dominated both the black carpet and today's headlines.

According to E! News, Cooper was appreciative that Gaga, his former costar, came out to support him. "It means the world to me," Cooper told E! News. "Also, because I'm really excited for her to see the movie. She's a dear friend and we went through such an incredible experience together, so you just want to share the art with each other."

You may recall that romance rumors swirled around Cooper and Gaga following their 2018 onscreen romance in "A Star is Born," rumors that peaked after an ultra-cozy performance of "Shallow" at the 2019 Oscars and Cooper's subsequent breakup with longtime girlfriend, Irina Shayk.

But aside from posing for a few photos with Cooper and co-star Carey Mulligan on Tuesday, as well as sharing a sweet moment with Cooper's daughter, Gaga respectfully kept a low profile and allowed those involved with "Maestro" to have their day in the sun.

Also turning heads at the premiere was Matt Bomer, who appears in "Maestro" as David Oppenheim, a Boston Symphony Orchestra clarinetist and gay lover of Bernstein's. Not only did Bomer look dashing in head-to-toe Tom Ford, but he walked the carpet with his "Fellow Travelers" costar Jonathan Bailey. For his work in "Fellow Travelers," Bomer received a Golden Globe nomination, nine years after the out actor received his first Globe nom for HBO's 2014 AIDS drama, "The Normal Heart."

Speaking to the Associated Press about working with Cooper on the film as both her co-star an director, two-time Oscar nominee Carey Mulligan, who stars as Bernstein's wife, gushed: "I don't know what it would be like with anyone else, but I'd never experienced it before. But with Bradley doing it, it was like no acting, we didn't have to act because he made it so easy ... But to do what he did, I think, is there's probably a handful of fie people in the world could do it."

Also speaking to AP at the premiere was Maya Hawke, the daughter of Uma Thurman and Ethan Hawke, who appears in the film as Bernstein's daughter, Jamie. "I think Bradley asked for a level of commitment from his cast that is something maybe only an actor could do," she shared. "You know, to understand the craft so well that, you know, when people aren't fully doing it and asking people to really bring their whole soul and spirit to the table. And so it was an amazing experience in that way."

While "Maestro" could certainly be called a biopic of the legendary music man, Cooper has said that he always intended the film to be a love story about the relationship with his wife, Felicia Montealegre. "Any time we were writing it," he shared with AP, "where elements seemed like it didn't have to do with us, we would just get rid of it."

"Maestro" is playing now in select theaters and will begin streaming Dec. 20 on Netflix. Watch the film's trailer here: