Johnny Depp
i've mentionned his 90s album
P on more than one occasion here. he's apparently played on some Oasis tracks, some soundtracks for his films, and with Shane MacGowan. but i like P best, featuring Gibby Haynes from the butthole surfers on vocals and random drummers and bassist (including Flea on some tracks).
here's their cover of Abba's Dancing Queen -
YouTube - P - Dancing Queen
i'm also old enough to remember Don Johnson's foray into pop music in the late 80s, same as Patrick Swayze. sometimes ability from one art doesn't translate that well to the other.
also the band Dogstar featured Keanu Reeves on bass, and apparently Richard Gere has a ridiculous collection of Les Pauls but i don't know if he's really tried branching out into music.
Chevy Chase is also a noted musician having played with both Steely Dan and Paul Simon.