I must say I was totally captivated by first hour and a half of this feature film.
After that, the story-telling became flawed, the film lost its way, and it simply became another aimless American saccharin attempt at emotional gut wrenching.
Despite this, memorable scenes for me were: the opening scene of an already burnt-out Jackson Maine (Cooper) trying to give it his all at a live gig, the tender parking lot scene on the night Jackson Maine and Ally (Gaga) met, and the scene where Jackson Maine brought Ally on stage for the first time and introduced her to the crowd.
Sam Elliot as Maine's half brother Bobby gave a convincing performance. I wasn't quite sure of Dave Chappelle's purpose as a character in the storyline, nor of him being properly cast in the first place. Perhaps he'd do better to stick to stand up comedy.
On the whole, I'd give the film 3.5*.
There is no doubt that similar genre film Bohemian Rhapsody completely eclipsed this film even were we to look only at the lead actor's performance.