Not sure if this is a movie. It's 2 parts about 2.5 hours each. It's the documentary Get Back on Disney+ (about the Beatles).
It uses footage shot over a couple of weeks in 1969 with the band prepping for their first live show in a couple of years.
It's long, it can drag because it's really just the band sitting and making up new music for this show on the fly. On the other hand, watching these guys just create some of their biggest hits out of thin air is amazing. They had 2 weeks before the show to create, practice and be ready to play 14 new songs on live TV in front of an audience.
If you like the Beatles or music in general, it's a pretty amazing look behind the scenes. These four guys sit and create music without arguing, bitching, yelling at each other etc. You can see they really were true friends at this point. Right up to the point where George says fuck you guys, I'm out.