Some of these arguably shouldn't be considered "musicians in movies" per se.
Jamie Foxx achieved fame through sketch comedy and was known as an actor first.
Similar situation with Donald Glover / "Childish Gambino". At the beginning of his stardom, he was known for comedic writing and acting. The public eye didn't start seeing him as a musician until he was arleady famous.
I guess it depends on how well known the celebrity is as a musician or otherwise. Sure, Jamie Foxx and Donald Glover might be known more as actors instead of musicians since that's more or less where they started from. But then, Ariana Grande started out on Broadway and was on a TV show before she became an international popstar, which is arguably what she's most famous for now.
Jamie Foxx achieved fame through sketch comedy and was known as an actor first.
Similar situation with Donald Glover / "Childish Gambino". At the beginning of his stardom, he was known for comedic writing and acting. The public eye didn't start seeing him as a musician until he was arleady famous.