Movie Stars that can handle musical instrument well

Russel Crowe plays smallest part in "his" band, because it's mostly pro musicians that you can give credit to, but definitely-most-definitely you can't give him credit neither for singing or playing 2...3 chords on guitar.

Johnny Depp. Only he doesn't just handle it. https://youtu.be/-X3hdFWmerQ?t=75

Jeff Goldblum Piano.

Not enough to be “triple threats” (act/sing/dance) in show business, they were pretty good instrumentalists as well:

https://youtu.be/baHH2Kqz1SQ

https://youtu.be/7bYvZEpHEMA

And, of course, an Academy award nomination for “Best Actor” makes one a movie star by any standard. He was inarguably a star as an instrumentalist. Some might even argue, the best tenor saxophone player of all time:

https://youtu.be/gIYV5kIdK9Q

Taking the twist on the OP a bit further, star instrumentalists who could handle a little acting:

https://youtu.be/YtjzVThkiFs

It's an old trick to include famous actor for better commercial success. Johnny Depp plays scored few notes on the guitar pretty clean, but still think it's more for commercial success than for the benefit of the gig.