Let’s see, Jason Schwartzman was the drummer of Phantom Planet, and he is now Coconut records, an indie pop solo project. He also played drums for his friend Nicole Simone.
Scarlett Johansson sings, or she thinks she can as she has released an album of Tom Waits covers, and another one with Pete Yorn.
Keanu Reeves was playing bass for the band Dogstar in the 90s.
Ryan Gosling is in this band Dead Man’s Bones with the Silverlake Conservatory Children’s Choir, the same conservatory started by Flea of the Red Hot Chili Pepper, and I had the pleasure to see Dead Man’s Bones at the FYF fest last year.
Zooey Deschanel is the half of She and Him with M. Ward, and she is also married to death Cab for Cutie’s Ben Gibbard
Jared Leto is the singer, guitarist and songwriter of the band 30 Seconds to Mars. With his brother, the drummer of the band, they have been very successful with already 3 albums.
Juliette Lewis was singing as Juliette and the Licks for a while, and I saw them several years ago at the Sunset Junction Fair. She has also formed the band The New Romantiques.
Adrian Grenier may play in the HBO series Entourage, but he also plays drums for The Honey Brothers.
Billy Bob Thornton (who apparently spent a lot of time with Lemmy at the rainbow grill) plays drums and sings with a country band, The Boxmasters, but he had already done a couple of other things in music before starting this band.
Kevin Bacon has formed a band with his brother in 1995, the Bacon Brothers band, and has released 6 albums since.
Kevin Costner has a country band called Modern West.
Russell Crowe has been in a few bands, he played guitar with the Australian 30 Odd Foot of Grunts, the Canadian Great Big Sea, and is currently playing with The Ordinary Fear of God.
Dennis Quaid plays with his band The Sharks.
I must have forgotten many…
By the way the Golden Globes best original song went to ‘You haven’t seen the last of me from Burlesque, and sung by Cher … I thought all the nominated the songs sounded the same anyway.